VIII IBERIAN CONFERENCE ON TRIBOLOGY

IBERTRIB 2015

VIII IBERIAN CONFERENCE

ON TRIBOLOGY CARTAGENA, 18 & 19 JUNE 2015

Conference Program and Handbook of Abstracts

OFFICIAL SPONSOR

COLLABORATING ENTITIES

Este trabajo es resultado de la ayuda 19591/OC/14 financiada por la Fundación Séneca-Agencia de Ciencia y Tecnología de la Región de Murcia con cargo al Programa “Jiménez de la Espada” de Movilidad, Cooperación e Internacionalización.

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VIII Iberian Conference on Tribology, IBERTRIB 2015

Index

Presentation………………………………………………..……………………….....3 History…………………………………………………………………………..3 Organization….………………………………………………………………...3 Conference topics.…………………………………………………………….3 Conference language..………………………………………………………..3

Committees……………………………………………………………………………4 Scientific Committee………………………………………………………….4 Organizing Committee………………………………………………………..5 Secretariat……………………….……………………………………………..5

Sponsors……………………………………………………………………………….6

General Information…………………………………………………………………..7 Conference venue.....………………………………………………………....7 Conference Proceedings….………………………………………………...10 Registration……..…………………………………………………………….10 Accommodation………………………………………………………………10 Internet………………………………………………………………………...11 Emergencies………………………………………………………………….11 Lunches and Conference Dinner …..………………………………………11 Social Program ……..………………………………………………………..11

Plenary Speakers……………………………………………………………………12

Conference program………………………………………………………………...14

Oral presentations…………………………………………………………………...19 Instructions for oral presentations.…………………………………………19 Thursday, 18th June…….…………………………………………………...20 Friday, 19th June…………………………………………………………….57

Posters………………………………………………………………………………...70 Instructions for poster presentations….……………………………………70 Posters………………………………………………………………………...71

List of participants……………………………………………………………………80

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Presentation

History

The first edition of the Iberian Conference on Tribology took place in Gijón in 2001, followed by Valencia 2003, Guimarães 2005, Bilbao 2007, Coimbra 2009, Madrid 2011 and Porto 2013.

Organization

The VIII Iberian Conference on Tribology -IBERTRIB 2015- is organized by the Materials Science and Engineering Research Group of the Materials and Manufacturing Engineering Department, Industrial Engineering School, at the Technical University of Cartagena (Spain) and is held during June 18th and 19th, 2015.

Conference Topics

- Friction and wear - Surface engineering, surface treatment and coatings - Lubrication, lubricants and additives - Biotribology - Micro and nanotribology - Contact mechanics - Modelling and simulation in tribology - Characterization techniques and testing methods in tribology - Case studies in tribology - Other topics in tribology

Conference Language

- The official language of the conference is English. - Abstracts, Extended Abstracts, Posters and Slides for presentations should be written in English. - Authors that do not feel comfortable with English language may present their papers either in Spanish or Portuguese.

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Committees

Scientific Committee

Marc Anglada Universidad Politécnica de Cataluña, España

Antonio Monteiro Baptista FEUP, Portugal

Manuel Belmonte I. de Cerámica y Vidrio-CSIC, España

Mª Dolores Bermúdez Universidad Politécnica de Cartagena, España

Armando Vilaça Campos ISEP-IPP, Portugal

Manuel Jorge Castro ISEP-IPP, Portugal

Albano Cavaleiro Universidade de Coimbra, Portugal

José Pimenta Claro Universidade do Minho, Portugal

Rogério Colaço IST, Portugal

Juan José Damborenea CENIM-CSIC, España

Paulo Davim Universidade de Aveiro, Portugal

Esteban Fernández Universidad de Oviedo, España

Luís Andrade Ferreira FEUP, Portugal

Carlos Ferrer Universidad de Politécnica de Valencia, España

José Gomes Universidade de Minho, Portugal

Beatriz Mata Graça INEGI, Portugal

Amaia Igartua Tekniker, España

Luís Leite Magalhães ISEP-IPP, Portugal

Ramiro Carneiro Martins INEGI, Portugal

António Sousa Miranda Universidade de Minho, Portugal

Amílcar Ramalho Universidade de Coimbra, Portugal

Jesús Rodríguez Universidad Rey Juan Carlos, España

J. Carlos Sánchez I. C. Materiales de Sevilla-CSIC, España

Jorge Oliveira Seabra FEUP, Portugal

Francisco Silva ISEP-IPP, Portugal

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Organizing Committee

Francisco José Carrión Vilches

Materials Science and Engineering Research Group

Materials and Manufacturing Engineering Department

Industrial Engineering School

Technical University of Cartagena

Ginés Martínez Nicolás

José Sanes Molina

Isidoro Martínez Mateo

Cayetano Espejo Conesa

Tulia Espinosa Rodríguez

Noelia Saurín Serrano

Joaquín Arias Pardilla

Ramón F. Pamies Porras

María Dolores Bermúdez Olivares

Ana Eva Jiménez Ballesta

Secretariat

Dr. Ana Eva Jiménez Ballesta

UNIVERSIDAD POLITÉCNICA DE CARTAGENA Dpto. de Ingeniería de Materiales y Fabricación Campus Universitario Muralla del Mar. ETSII. C/ Doctor Fleming, s/n. – 30202 CARTAGENA España

Contact:

Email: [email protected] Phone: +34 968 32 65 06 / 968 32 59 60

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Sponsors

Official Sponsor

SGS España

C/Trespaderne 29. Edificio Barajas I Madrid, 28042, Spain

Tel. +34 91 313 80 00 Fax +34 91 313 80 80

Collaborating Entities

Este trabajo es resultado de la ayuda 19591/OC/14 financiada por la Fundación Séneca-Agencia de Ciencia y Tecnología de la Región de Murcia con cargo al Programa “Jiménez de la Espada” de Movilidad, Cooperación e Internacionalización.

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General Information

Conference Venue

UNIVERSIDAD POLITÉCNICA DE CARTAGENA Campus Universitario Muralla del Mar. ETSII. C/ Doctor Fleming, s/n. – 30202 CARTAGENA

The historical city of Cartagena belongs to the autonomous province of Murcia. Cartagena is located in the southeast of Spain, right at the Mediterranean Sea.

The Technical University of Cartagena is simultaneously a city and a campus University. Many buildings of the University played an important role in the 18th century, as they were used as naval hospitals, prisons, barracks, or as Navy schools. All buildings were completely renewed and restored.

The School of Industrial Engineering is located in the historic building of an old military hospital for the Navy. This building of 30,000 square meters houses several classrooms, departmental offices, services and laboratories.

Today, the Old Hospital, with its 170 meter façade, has three floors, a basement and a penthouse floor (attic) and has a capacity for 1,600 students.

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NH Hotel

Los Habaneros

Hotel

University Main

Entrance

Conference Restaurant

Roman Theatre

IBERTRIB 2015

NH Hotel

Los Habaneros

Hotel

University Main

Entrance

Conference Restaurant

Roman Theatre

Carlos III Hotel

Cartagonova Hotel

Carlos III Hotel

Cartagonova Hotel

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Ground floor

First floor

Second floor

University Main Entrance

Registration desk (Lobby A)

Stairs to 1st floor

Stairs to 2nd floor

Room A

Coffee break

Room B

Posters (Lobby B)

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Technical Exhibition (Lobby A)


Conference Proceedings

All the accepted full papers will be published in the Conference Proceedings in electronic format (with ISBN). To be included in the Conference Proceedings at least one of the authors of the paper must be registered. Once the conference is finished, the proceedings will be available in the Digital Repository of the Universidad Politécnica de Cartagena.

Registration

18th June: from 8:30h to 9:15h. 19th June: from 8:30h to 9:00h.

Participants should collect their name badges from the congress registration desk. Since only registered participants will be permitted to attend the scientific sessions, coffee breaks, exhibition areas and lunches, participants are kindly requested to wear their badges when entering the conference venue.

All registered delegates are entitled to one copy of the Book of Abstracts, CD-ROM/PEN-DRIVE with full-papers, and to attend all technical sessions, conference dinner, refreshments and lunches. Each registration fee allows the publication of a maximum of 2 papers.

Certificates of attendance can be requested at the registration desk.

Accommodation

Hotel Los Habaneros (***) Calle San Diego, 60, 30202 Cartagena, Murcia Tel. +34 968 50 52 50 www.hotelhabaneroscartagena.com

Hotel NH Cartagena (****) Plaza Héroes de Cavite, s/n, 30201 Cartagena, Murcia Tel. +34 968 120 908 www.nh-hoteles.es/nh/es/hoteles/espana/cartagena/nh-cartagena.html

Hotel Sercotel Carlos III (***) Calle Carlos III, 49, 30203 Cartagena, Murcia Tel. + 34 968 520 032 www.carlosiiihotel.com

Hotel Cartagonova (****) Calle Marcos Redondo, 3, 30201 Cartagena, Murcia. Tel. +34 968 50 42 00 www.hotelcartagonova.com

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Internet

Free WiFi on site. The password and the user name will be provided at the

registration desk.

Emergencies

Emergency phone is free of charge: 112.

Lunches and Conference Dinner

All lunches and the Conference Dinner will be held

at the Restaurant Eszencia.

The Conference Dinner will be held on June 18, starting from 20:30h.

Eszencia Restaurant Auditorio y Palacio de Congresos El Batel Paseo Alfonso XII, S/N, 30201 Cartagena, Murcia

Social Program (Cartagena Puerto de Culturas Touristic Visit)

The Touristic visit will be held on June 18 from 19:00 to 20:00h.

THE ROMAN THEATRE MVSEUM IN CARTAGENA

The regeneration project of the Roman Theatre in Cartagena has taken into account the integration of the remains in the urban network, as well as its adequate preservation and presentation for learning and cultural purposes. Also, the considerable wealth of the pieces for the successive excavation campaigns discovered in the Theatre have given the opportunity to provide the city with a new museum space, the Roman Theatre Mvseum, that not only serves as an adequate exhibition framework, but also, in the bright concept of the architect Rafael Moneo, leads the visitors to the interior of the monument, converting the Roman Theatre into its ultimately great hall.

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Plenary Speakers

The conference program includes two Keynote Plenary Lectures by distinguish scientists in the field of Tribology, to provide thematic presentations on their most recent findings.

Lecture 1:

Dr. Luis Fernández Ruiz-Morón, head of the Tribology area in the Lubricant Laboratory of Repsol S.A.

Luis Fernández Ruiz-Moron, Doctor and Industrial Engineer from the Polytechnic University of Madrid, works at Repsol since 2002 at the Technology Directorate, leading R & D projects of industrial lubricants, fluids for shock absorbers, fluids for manual and automatic transmissions, and he is currently working on the development of high efficiency lubricants. He is responsible for the area of tribology in a lubricants laboratory. He previously worked at the Department of Biomechanics at INSIA (Center for Automotive Research). In addition, he is an expert researcher evaluator of the National Evaluation Agency (ANEP) and he is also an ISO / AENOR Accredited Expert Member and a member of various European groups.

Lecture: “Tribology: key for fuel efficiency”

Emission regulation and environmental restrictions among others are driving a change in lubricant market. Lubricant composition is becoming more and more complex. Dedicated lubricants are being demanded more and more. The industry is requiring lubricants that make the machines to run smoother, at lower temperatures and more efficient for longer drain intervals.

Tribology is playing a key role in lubricant development. There are a few factors that must be taken into account and are review in this work, such as operating conditions, materials, coatings, specific engine design, auxiliary system, etc.

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Lecture 2:

Prof. Dr. Nicholas Spencer, head of the Laboratory for Surface Science and Technology of the ETH Zürich.

Nicholas Spencer studied at the University of Cambridge, where he obtained a Bachelor's degree in Chemistry and earned his Ph.D. in the area of Surface Chemistry in 1980. Following this, he worked as a postdoctoral fellow at the University of California, Berkeley, where he studied ammonia synthesis catalyzed by iron single crystals. From 1982 to 1993 he was employed at the Research Division of W. R. Grace and Co. in Columbia, Maryland, working in the areas of catalyst research, high-temperature superconductors, and finally as head of the surface science, microscopy, and vibrational spectroscopy groups. Since August 1993 he has been Professor for Surface Science and Technology at the ETHZ (Zürich, Switzerland), and from 1996 to 1998 and 2002 to 2006 served as Chair and Head of the Department of Materials. He is the President of the ETH Research Commission at the moment. He is editor-in-chief of the journal Tribology Letters. (http://www.surface.mat.ethz.ch/people/professors/spencern)

Lecture: “Tribological and Mechanical Properties of Polymer Brushes and Brush-Gels”

Most natural surfaces with tribological significance are soft, and decorated with sugar-based chains that dangle into the surrounding aqueous environment. One way in which such structures can be imitated in the laboratory is in the form of polymer brushes, which exhibit many interesting properties, both tribological and biological. Polymer brushes with a certain degree of crosslinking are essentially gels (“brush-gels”), which also resemble natural soft materials such as cartilage or the surface of the cornea. In our laboratories, we have utilized polymer brushes and brush-gels for lubrication, at first in aqueous environments and more recently in oil. They exhibit very promising frictional behaviour, but present challenges as far as wear is concerned. An important factor in these materials is the interplay between the solvent (oil or water) and the polymer, not only in terms of solvation, but also in a dynamic sense, i.e. how the solvent behaves within the polymer construct under sliding contact. By means of a judicious choice of solvent quality and viscosity, a significant amount of the load on the polymer brush system can be borne by the solvent, as it is pushed through the porous network of the brush or brush-gel, thereby protecting the polymer from excessive wear.

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Conference program Thursday, 18th June

8:30-9:15 Registration (Lobby A)

Session A1 (Room A) Opening and Keynote Lecture 1.

Chair: Prof. Dr. María Dolores Bermúdez

9:15-9:30 Opening: Scientific Committee and Collaborating Entities

9:30-10:30 Keynote Lecture: Dr. Luis Fernández Ruiz-Morón (Repsol S.A.). "Tribology: key for fuel efficiency"

10:30-11:00 Coffee break/Poster Sessions/Technical Exhibition (Lobby A & Lobby B)

Session A2 (Room A) Lubrication, lubricants and additives. Chair: Dr. Luis Fernández Ruiz-Morón

Session B2 (Room B) Friction and Wear.

Chair: Prof. Dr. Jesús Rodríguez Pérez

11:00-11:20

A2.1 "Assessment of low viscosity engine oils in

terms of fuel consumption and engine wear in Heavy Duty Engines Fleet Test"

Guillermo Miró Mezquita (Lub_01_Miro)

B2.1 "Tribological behaviour of silicon

carbide/graphene nanoplatelets composites under dry sliding conditions"

Javier Llorente Dueñas (Fri_01_Llorente)

11:20-11:40

A2.2 " Mechanisms of Varnish Formation and

Implications for the Use of Soluble Varnish Removal Technology "

Matthew Hobbs (Lub_02_Hobbs)

B2.2 "Influence of the direction fiber on the

tribological behavior of carbon-fiber reinforced epoxy composites manufactured by prepeg

laminates" Juana Coello Sobrino

(Fri_04_Coello)

11:40-12:00

A2.3 "Improving wear performance of wind turbine gearboxes using ionic liquids as additives of

lubricants" Patricia Iglesias Victoria

(Lub_03_Iglesias)

B2.3 "Physical and tribological characterization of

four commercial braking formulation materials" Pedro V. Antunes (Fri_05_Antunes)

12:00-12:20

A2.4 "Molecular design of halogen free room-temperature ionic liquids for lubricants:

Tetraalkylphosphonium alkylsulphonates" Catur Y. Respatiningsih

(Lub_04_Minami)

B2.4 "Tribological behavior of functionalized 1-2 Layered graphene/UHMWPE composites"

Jose Antonio Puértolas Rafales (Fri_06_Pascual)

12:20-12:40

A2.5 "Power loss of FZG gears lubricated with wind

turbine gear oil using ionic liquid additive" Jorge H. O. Seabra

(Lub_05_Seabra)

B2.5 "Wear behavior of cryogenically treated AISI

420 martensitic stainless steel" Germán Prieto (Fri_07_Prieto)

12:40-13:00

A2.6 "Use of NTf2 anion-based ionic liquids in the

formulation of gear oils" Alberto García Martinez

(Lub_06_Garcia)

B2.6 "Tribological study of the AISI316L/Sapphire

contact with self-lubricating films of protic ionic liquids"

Tulia Espinosa Rodríguez (Fri_08_Espinosa)

13:00-15:00 Lunch

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Thursday, 18th June Session A3 (Room A)

Case Studies. Chair: Dr. Juan Carlos Sánchez López

Session B3 (Room B) Biotribology.

Chair: Dr. Patricia Iglesias Victoria

15:00-15:20

A3.1 "Efficiency prediction on a 2.5 MW wind

turbine gearbox" Carlos Fernandes

(Cas_02_Fernandes)

B3.1 "Abrasive and sliding wear of resin composites

for dental restorations" José R. Gomes (Bio_02_Gomes)

15:20-15:40

A3.2 "Influence of grease formulation on rolling

bearings friction torque" Jorge H. O. Seabra (Cas_03_Goncalves)

B3.2 "Development of the microbiological

population in water miscible metal working fluids"

Benedikt Seidel (Bio_03_Seidel)

15:40-16:00

A3.3 "Gear Scuffing: Power dissipation and mass

temperature" Jorge Castro

(Cas_04_Castro)

B3.3 "Friction of Human skin against different

hospital fabrics" Luis M. Vilhena (Bio_04_Vilhena)

16:00-16:20

A3.4 "Study on the wear and rolling contact fatigue behavior or rail steel grades by using a twin

disc laboratory equipment" María Panera Castro

(Cas_06_Panera)

B3.4 "Biofilm influence on the pair tribological wear

tooth-zirconia" Carla María Carneiro

(Bio_05_Carneiro)

16:20-16:40

A3.5 "Analysis of valve and valve seat insert

damage morphology observed after different engine tests"

Alexander Zuleta Durango (Cas_05_Zuleta)

B3.5 "The tribological behaviour of a newly

developed water absorbable Skin Equivalent compared to isolated human skin during

sliding" Marina Morales Hurtado

(Bio_01_Morales) 16:40-17:10 Coffee break/Poster Sessions/Technical Exhibition (Lobby A & Lobby B)

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Thursday, 18th June Session A4 (Room A)

Modelling and Simulation/Characterization Techniques

Chair: Dr. Manuel Belmonte Cabanillas

Session B4 (Room B) Biotribology/Tribocorrosion.

Chair: Prof. Dr. José R. Gomes

17:10-17:30

A4.1 "Wear model for reciprocating ball-on-flat wear

tests" Miguel Esteves

(Mod_02_Esteves)

B4.1 "Evaluation of tribological properties of new

Alumina/Zirconia Ceramics for dental restoration"

Celio Figueiredo Pina (Bio_06_Figueiredo)

17:30-17:50

A4.2 "Analysis of Temperature and Pressure

Distribution on Deformable Short Lubricated Bearings"

Luigi C. Greco (Mod_03_Greco)

B4.2 "Biotribology study for determining the

influence of surface modification in PEEK and UHMWPE in the reduction of particles

releasing for knee prosthesis application" Cristina Díaz Jiménez

(Bio_07_Diaz)

17:50-18:10

A4.3 "Study of creep function determination of two

amorphous polymers by indentation technique" Miguel Ángel Garrido

(Ctt_02_Garrido)

B4.3 "Wear and corrosion behaviour of CoCrMo biomedical alloy in presence of hydrogen

peroxide" Anna Neus Igual Muñoz

(Bio_08_Igual)

18:10-18:30

A4.4 "Study on the rolling contact fatigue behavior

of rail steel grades" Pablo García Suarez

(Ctt_03_Garcia)

B4.4 "Tribocorrosion behaviour of mooring HSLA

steel in synthetic seawater under bidirectional sliding"

Ainara López (Tri_02_Lopez)

18:30-19:00 Scientific Committee Meeting IBERTRIB 2017 (Room A)

19:00-20:00 Social Program (Cartagena Puerto de Culturas Touristic Visit)

20:30-23:00 Conference Dinner

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Friday, 19th June 8:30-9:00 Registration (Lobby A)

Session A5 (Room A) Keynote Lecture 2.

Chair: Prof. Dr. Jorge H. O. Seabra

9:00-10:00 Keynote Lecture: Prof. Dr. Nicholas Spencer (ETH Zürich). "Tribological and Mechanical Properties of Polymer Brushes and Brush-Gels"

10:00-10:30 Coffee break/Poster Sessions/Technical Exhibition (Lobby A & Lobby B)

Session A6 (Room A)Tribocorrosion/Micro and

Nanotribology. Chair: Prof. Dr. Anna Neus Igual Muñoz

Session B6 (Room B) Surface Engineering.

Chair: Prof. Dr. Jorge H. O. Seabra

10:30-10:50

A6.1 "The effect of fuel dilution and oil aging of

lubricants on the piston ring/liner tribochemistry for HDVs using used cooking oil

as a fuel" Chun Wang

(Tri_01_Wang)

B6.1 “Tribological properties of plunging-type

textured surfaces produced by modulation-assisted machining"

Patricia Iglesias Victoria (Sur_01_Iglesias)

10:50-11:10

A6.2 "Mechanism of tribo-chemical reactions of

ionic liquids on titanium alloys" Amaya Igartua (Tri_03_Igartua)

B6.2 "Tribological properties of TiC/a-C:H

nanocomposite coatings prepared by HiPIMS" Juan Carlos Sánchez López

(Sur_02_Sanchez)

11:10-11:30

A6.3 "Study of the isothermal oxidation treatments effect on the local wear behaviour of Inconel

625 coatings deposited by laser cladding" Davide Verdi

(Micro_02_Verdi)

B6.3 "Wear and high temperature wear on MCrAl

alloy on HVOF" Juan Vicente Miguel Guillem

(Sur_03_Amigo)

11:30-11:50

A6.4 "Wear resistant in-situ carbon

nanotubes/silicon nitride nanocomposites with a high loading of nanotubes"

Manuel Belmonte Cabanillas (Micro_03_Belmonte)

B6.4 "Lubricious TiSi(V)N coatings for extreme

temperature application deposited by Deep Oscillation Magnetron Sputtering (DOMS)

mode" Filipe Fernandes

(Sur_04_Fernandes)

11:50-12:10

A6.5 “Study of the abrasion resistance of new

epoxy (ER) – ionic liquid (IL) materials with self-healing ability"

Noelia Saurín Serrano (Micro_04_Saurin)

B6.5 "Effect of spinels on the mechanical and tribological behavior of plasma sprayed

alumina based coatings" Alvaro Rico García

(Sur_05_Rico)

12:10-12:30

B6.6 "Tribosystems based on self-mated multilayer

micro/nanocrystalline HFCVD diamond coatings: effects of humidity and temperature"

Cristiano S. Abreu (Sur_06_Abreu)

12:30-13:00 Conference Closure and presentation of the IX IBERTRIB Edition (Room A)

13:00-15:00 Lunch

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Poster Session

Session P1 (Lobby B) Friction and Wear

Session P2 (Lobby B) Surface Engineering

P1.1 "The minimum quantity of lubricant technique

in grinding of steel using a wheel cleaning system"

Eduardo Carlos Bianchi (Fri_P01_Bianchi)

P2.1 "Laser deposition of alumina and carbon black

on AISI 4340 steel" Getulio Vasconcelos

(Sur_P01_Vasconcelos)

P1.2 "Grinding of AISI 4340 steel when interrupted

cutting by aluminum oxide grinding wheel" Hamilton Jose de Mello

(Fri_P02_de_Mello)

P2.2 "High temperature tribological characterization of TiAl laser cladding coating on Ti6Al4V alloy"

Juan Carlos Pereira (Sur_P02_Zambrano)

P1.3 "Wear behaviour of ceramic composites for

grinding wheel: Effect of sintering temperature" José R. Gomes

(Fri_P03_Gomes)

P2.3 "Development of laser cladding MCrAlY

coatings: high temperature friction and wear behavior"

Juan Carlos Pereira (Sur_P03_Pereira)

P1.4 "Abrasive wear mechanisms of gray cast iron.

Application to cylinder bore abrasion" Luiz Alberto Franco

(Fri_P04_Franco)

P2.4 "Biotribological behavior of anti-bacterial Ag-C coatings prepared by DC-pulsed magnetron

sputtering" Juan Carlos Sánchez López

(Sur_P04_Sanchez)

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Oral presentations

Instructions for oral presentations

All submissions will be peer-reviewed based on originality, technical quality and presentation, and those accepted will appear in the Book of Abstracts which will be made available to delegates of IBERTRIB 2015 during the event.

Speakers are requested to upload their file to the computer on the corresponding room before 9:00 am, if their presentation is in a morning session, or before 14:30, in case of an afternoon session. Presentations may be transferred via USB device, CD-R or DVD. Speakers can also upload their files at the registration desk during the Conference hours.

Oral presenters will have a 15 minutes-talk, including 3 minutes for questions.

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Thursday, 18th June SESSION A2

Lubrication, lubricants and additives. Chair: Dr. Luis Fernández Ruiz-Morón

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Assessment of low viscosity engine oils in terms of fuel consumption and engine wear in Heavy Duty Engines Fleet Test.

Vicente Macián (a), Bernardo Tormos (a), Santiago Ruiz (a), Guillermo Miró* (a) and Tomás Pérez (b)

a CMT-Motores Térmicos, Universitat Politècnica de València, Spain

b Repsol S.A., Spain

* [email protected]

Due to the increasingly stringent emissions standards in the world and, on the other hand, the foreseen shortage of fossil fuels, the application of low viscosity engine lubricants (LVO) is considered one of the most interesting option for counter these threats. The aim of the test was to verify the fuel consumption benefits of LVO in Heavy Duty Vehicles (HDV) found in previous works, which were obtained mainly in engine test bench, when they are working on real and “on-Road” conditions. Parallel to this study, the performance of low viscosity lubricants regarding to engine wear was verified, since the use of LVO could imply an increase in wear rate. Potential higher wear could result in a reduction in life cycle for the internal combustion engines, a non-desired effect. In order to achieve this goal, a sample of 39 urban buses comprising two engine technologies (Diesel and Compressed Natural Gas (CNG)) and four different lubricants was studied over an Oil Drain Interval (approx. 30000 km), measuring daily mileage and fuel consumed to calculate each bus fuel consumption, and also they were monitored (each 3000 km) using a deep and extensive oil analysis program, and specially engine wear was quantified using Inductively Coupled Plasma - Optical Emission Spectroscopy (ICP-OES), in order to detect abnormal wear patterns in the engine.

Results obtained have shown a positive correlation between the use of LVO and fuel consumption reduction in HDV, both for Diesel and CNG. Regarding to oil performance, results indicate that engine wear do not show abnormal patterns due to use of LVO.

A2.1

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Mechanisms of Varnish Formation and Implications for the Use of Soluble Varnish Removal Technology

Matthew G. Hobbs (a), Peter Dufresne Jr. (a),* Shirin Behyan (b), Pierre Kennepohl (b) and John Evans (c)

a EPT, 4772 50th Avenue S.E. Calgary, AB, Canada.

b Department of Chemistry, University of British Columbia, Vancouver, BC, Canada.

c Hy-Pro Filtration, 6810 Layton Road, Anderson, IN, USA.

* [email protected]

Varnish is an organic deposit produced by chemical degradation of mineral oil lubricants. Varnish can lead to numerous equipment problems including: filter plugging, restricted oil flow, poor heat transfer, valve sticking, fail-to-start conditions and unit trips.

As a consequence of the costly and prevalent nature of varnish-related failures, a number of studies have sought to elucidate the mechanism by which varnish forms. In all cases, oxygen is presumed to initiate oil breakdown through radical processes. These studies have focused upon the characterization of final oil oxidation products. In an effort to directly measure radical intermediates involved in thermo-oxidative lubricant degradation, we employed electron paramagnetic resonance (EPR) spectroscopy to gain additional insight into the mechanism of varnish formation.

The species observed by EPR spectroscopy suggest that oxygen plays a more significant role in the termination of radical processes than it does in their initiation. Even under anaerobic conditions, oil breakdown produces radicals. If these radicals are exposed to oxygen, polar, soluble varnish precursors form; these species eventually aggregate in the non-polar base oil matrix, forming insoluble varnish.

Numerous strategies for varnish removal have been developed. Most technologies focus on the removal of insoluble varnish particles by mechanical or electrostatic filtration. Unfortunately, these systems have no effect upon the polar soluble varnish precursors which arise when oil breakdown products are trapped by oxygen. Rather than simply filtering suspended particles, soluble varnish removal systems remove these soluble precursors by exploiting their unique chemistry. When these varnish precursors are removed, even lubricants exposed to extreme thermo-oxidative conditions show no propensity for varnish formation.

As a breakdown initiator, oxygen need only be present in catalytic amounts, however, as a radical trap, stoichiometric quantities are required for varnish formation to occur. Strategies aimed at controlling lubricant oxygen concentrations are, therefore, likely to further mitigate the risk of insoluble varnish formation in critical systems.

A2.2

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Improving wear performance of wind turbine gearboxes using ionic liquids as additives of lubricants

Patricia Iglesias (a)*, Kelly McNabb (a)

a Department of Mechanical Engineering, Rochester Institute of Technology,

72 Lomb Memorial Drive, Rochester, NY, USA.

* [email protected]

Wind resources are a proven source of clean, affordable and sustainable energy. Wind energy does not produce harmful pollution gases such carbon dioxide, sulfur dioxide, or other gases that have contributed to global warming. The wind energy industry has seen rapid growth within the last decade; however the cost of maintain the turbines is a major drawback. Wind turbine gearboxes present one of the more challenging current practical tribological problems. Contact failures in gear and bearing components have been the source of costly repairs and downtime of the turbine’s drivetrain and actuator [1,2]. A potential solution to reduce contact failures in wind turbines and increase their lifespan, is the use of ionic liquids (IL) as lubricant or additives of lubricants. ILs have the ability to form stable ordered layers on the contact area between the materials, reducing friction and wear [3].

In this work, the wear behavior of trihexyltetradecylphosphonium bis(trifluoromethylsulfonyl) amide used as additive (5 wt%) in a base oil is studied and compared to commercially available fully formulated lubricant. Lubricated disks of steel AISI 52100 mated with AISI 440C stainless steel balls are studied using a ball-on-flat reciprocating configuration under variable conditions of normal applied load and sliding frequency. The use of the IL as additive in a base oil reduce wear, particularly under the lowest frequency studied. The wear mechanisms and surface interactions are discussed in terms of IL-metal surface interactions from SEM, EDX and XPS data.

References:

[1] Greco, A., Sheng, S., Keller, J., and Erdemir, A., 2013, "Material Wear and Fatigue in Wind Turbine Systems", Wear, 302(1-2), pp. 1583-1591.

[2] Greco, A., Mistry, K., Sista, V., Eryilmaz, O., and Erdemir, A., 2011, "Friction and Wear Behaviour of Boron Based Surface Treatment and Nano-Particle Lubricant Additives for Wind Turbine Gearbox Applications", Wear, 271(9-10), pp. 1754-1760.

[3] Bermudez, M. D., Jimenez, A. E., Sanes, J., and Carrion, F. J., 2009, "Ionic Liquids as Advanced Lubricant Fluids", Molecules, 14, pp. 2888–2908.

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Molecular design of halogen free room-temperature ionic liquids for lubricants: Tetraalkylphosphonium alkylsulphonates

Ichiro Minami (a)*, Catur Y. Respatiningsih (a) and Gen Masuda (b)

a Luleå University of Technology, Sweden

b Nisshinbo Holdings Inc., Japan

* [email protected]

Room-temperature ionic liquids (RTIL) are molten salts that melt below room temperatures. They possess outstanding physical and chemical properties that are desirable for advanced lubricants [1]. Most available RTIL at present are composed of fluorine atoms in anionic moiety. Since halogens are prone to react with metallic materials under tribological conditions, corrosion is one of the serious drawbacks of RTIL as lubricants. Our previous works [2-4] indicated that halogen free RTIL can lubricate steel-steel contact if appropriate additives were applied. This is a series of work on molecular design of lubricants [5].

Novel RTIL were designed by the combination of tetraalkylphosphonium cation with substituted alkylsulphonate anions. They appear viscous fluids at room temperature. Their tribological properties were evaluated as pure substances (without additives) according to ASTM D 6425 procedure (SRV type tribometer) using a steel ball and a steel flat in reciprocating motion.

The RTIL provided low and stable friction in comparison with commercially available fully formulated lubricants, especially under extreme conditions such as high load and temperature. Wear on flat surface was slight: a little larger width than the Hertzian contact deformation and non-measurable depth by a non-contact surface profilometer. The designed RTIL provided better tribological properties than N,N-dialkylimidazolium bis(trifluoro-methanesulfonyl)amide, the reference RTIL, did. Possible lubrication mechanism in the light of molecular structure and the tribological properties will be discussed herein.

References: [1] I.Minami, Ionic liquids in tribology, Molecules, 14 (2009) 2286. [2] I.Minami, et al., Tribological properties of halogen-free ionic liquids, Journal of

Engineering Tribology, 226 (2012) 891. [3] V.Totolin, et al., Halogen-free borate ionic liquids as novel lubricants for

tribological applications, Tribology International, 67 (2013) 191. [4] V.Totolin, et al., Lubrication Mechanism of Phosphonium Phosphate Ionic Liquid

Additive in Alkylborane–Imidazole Complexes, Tribology Letters, 53 (2014). [5] I.Minami, et al., Concept of molecular design towards additive technology for

advanced lubricants, Lubrication Science, 19 (2007) 127.

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Power loss of FZG gears lubricated with wind turbine gear oil using

ionic liquid additive

Carlos Fernandes (a)*, Ramiro Martins (a), Jorge H. O. Seabra (b),Raquel Monge (c), José L. Viesca (d), Alberto García (d), Rubén

González (e) and Antolin Hernandez Battez (d)

(a) INEGI, Universidade do Porto, Campus FEUP, Rua Dr. Roberto Frias 400,

4200-465 Porto, Portugal

(b) FEUP, Universidade do Porto, Rua Dr. Roberto Frias s/n, 4200-465 Porto,Portugal

(c) Engineering Division, CELLS – ALBA Synchrotron Light Facility, Barcelona, Spain

(d) Department of Construction and Manufacturing Engineering, University of Oviedo,Asturias, Spain

(e) Department of Marine Science and Technology, University of Oviedo, Asturias,Spain

* [email protected]

Based on the good anti friction behaviour, hydrophobicity and hydrolytic stability ofthe [NTf2] anion reported by Minami et al. [1, 2], the current work studies thetribological performance of [BMP][NTf2] ionic liquids (1-butyl-1-methylpyrrolidiniumbis (trifluoromethylsulfonyl)imide) used as additive of a fully formulated wind turbinegear oil in a concentration of 5 wt%. The study is based on the power loss and wearof FZG gear tests and rolling bearing friction torque tests.

The FZG power loss tests showed that MINR + 5% IL can promote a reduction inpower loss up to 20% in comparison to MINR. Additionally, MINR + 5% IL promotedmuch lower mass loss and simultaneously seems to promote lower surfaceroughness variation than MINR.

References:

[1] I. Minami, M. Kita, T. Kubo, H. Nanao, S. Mori, The tribological properties of ionicliquids composed of trifluorotris(pentafluoroethyl) phosphate as a hydrophobic anion,Tribology Letters 30 (3) (2008) 215–223. doi:10.1007/s11249-008-9329-y.

[2] I. Minami, Ionic liquids in tribology, Molecules 14 (6) (2009) 2286–2305.doi:10.3390/molecules14062286.

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Use of NTf2 anion-based ionic liquids in the formulation of gear oils

A. García (a)*, R. Monge (b), J.L. Viesca (a), A. Fernández-Gonzalez (c),R. González (d), A. Hernández Battez (a)

a Department of Construction and Manufacturing Engineering, University of Oviedo,Spain

b Engineering Division, CELLS - ALBA Synchrotron Light Facility, Barcelona, Spain

c Department of Physical and Analytical Chemistry, University of Oviedo, Spain

d Department of Marine Science and Technology, University of Oviedo, Spain

* [email protected]

Wind turbines are an important source of renewable energy broadly used in electricitygeneration. The gearbox has the higher repair costs and greater downtimes in windturbines. Reduce the friction loses in the gearbox is very important for betterefficiency, but also is very interesting to increase the wear resistance in order toimprove the availability of the machine and reduce maintenance costs.

This work presents the friction and wear behaviour of two fully formulated ISO VG320(polyalphaolefin- and mineral-based) wind turbine gearbox oils separately additivatedwith two ionic liquids ([Choline][NTf2] and [BMP][NTf2]) at 5 wt% concentration. Theresults have been compared to the fully formulated oils without ionic liquids.

Ball-on-plate reciprocating friction and wear tests were performed at 60 and 100 N(corresponding with a maximum pressure of 1.91 and 2.26 GPa, respectively) andtemperatures of 40 and 100ºC. Due to the harsh conditions tests at 100 N load wereonly performed at 40ºC. Friction coefficient was recorded during tests and aftertribological tests the worn surface was measured and analysed by confocalmicroscopy, SEM, EDS and XPS.

The friction and wear results showed that both ionic liquids used as an additive havea slight friction modifier character but a strong wear reducing performance, with[BMP][NTf2] performing better than [Choline][NTf2]. In addition, EDS and XPSanalysis demonstrated the temperature-related chemical interactions and theirinfluence on tribological behaviour.

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mailto:[email protected]


Thursday, 18th June SESSION B2

Friction and Wear. Chair: Prof. Dr. Jesús Rodríguez Pérez

27


Tribological behaviour of silicon carbide/graphene nanoplatelets composites under dry sliding conditions

Javier Llorente*, Benito Román, Pilar Miranzo and Manuel Belmonte

Institute of Ceramics and Glass (ICV-CSIC), Kelsen 5, 28049 Madrid, Spain

* [email protected]

Silicon carbide (SiC) stands out, among advanced engineering ceramics, for a combination of excellent properties. Particularly, its high hardness and stiffness, high wear resistance and good chemical inertness at elevated temperature, allow its use in applications where a good tribological performance is required (cutting tools, bearing parts, etc.). On the other hand, the new demanding working conditions, linked to energy savings and ecological issues, require new materials with enhanced tribological properties and, to achieve this goal, we propose the addition of graphene as filler to silicon carbide.

In the present work, dense and homogenous SiC/graphene nanoplatelets (GNPs) composites containing up to 20 vol.% of the nanocarbon filler were fabricated by a liquid-phase spark plasma sintering (SPS) process. Dry reciprocating ball-on-plate wear tests were performed, where the plates corresponded to the SiC composite material and the balls were commercial silicon nitride ceramics. The tests were conducted at 5 N, stroke length of 2.5 mm, frequency of 20 Hz, and sliding distance of 360 m. The friction coefficient and the wear resistance of the materials were evaluated as a function of the GNPs content (0, 5, 10, and 20 vol.%). Worn surfaces were characterized by scanning electron microscopy and micro-Raman spectroscopy.

The friction coefficient considerably decreased with GNPs content for sliding distances below 50 m, while the effect of the nanocarbon fillers was almost negligible for larger distances. Besides, the exfoliation of the nanoplatelets creates an adhered protective tribofilm on the component surface that leads to an increased wear resistance (up to 70% compared to the unfilled material).

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Influence of the direction fiber on the tribological behavior of carbon-fiber reinforced epoxy composites manufactured by prepeg

laminates.

J. Coello (a,b)*, A. Martínez (a), A. Castillo (b) and V. Miguel (a,b)

a Regional Development Institute, University of Castilla-La Mancha, Campus Universitario 02006 Albacete (Spain)

b Industrial Engineers School, University of Castilla-La Mancha, Campus Universitario 02006 Albacete (Spain)

* [email protected]

Nowadays, fiber reinforced polymers composites are often used in variety of industrial applications such as bearings, rollers, gears and transmission belts. In these applications it is necessary high strength and stiffness, great thermal and dynamic mechanical stability and good tribological properties. Therefore, carbon-glass short fibers are frequently used for reinforcement in those uses.

The objective of the present work is to evaluate the wear behavior of different carbon fiber reinforced epoxy composites under different load and sliding velocity. The influence of fiber direction was studied too.

The material considered in this study was a pre-peg UMECO VTS263, consisting of 60% in volume of unidirectional carbon fibers in an epoxy syntactic matrix.

Three 60x60mm2 laminates composites were manufactured varying the lay-up angle (0º, 90º and multidirectional) and the number of plies. All laminates were cured at 120ºC during 3 hours.

The friction and wear tests were carried out on a pin-on-disk tribometer with F520 steel flat pin of 3mm diameter. Prior to each test, the pin was polished with 220 grind paper to a roughness Ra 0,2µm. The sliding was performed with different loads (10-40N) and velocities (1-3 rps) and under dry conditions.

Surface finishing after every test was evaluated by measuring with a 3D profilometer and by optical microscopy. Coefficient of friction (COF) and wear depth were obtained as a function of the friction variables and the sliding distance.

The results showed an important COF decreasing with the sliding velocity while the pressure tends to increase the COF. In every test, two different tribological behaviors were identified depending on the sliding distance and according to the point in which the epoxy resin was removed.

The lay-up angle strongly affected the obtained results. The laminates with multidirectional fibers threw the best behavior from the wear viewpoint.

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Physical and tribological characterization of four commercial

braking formulation materials

P.V. Antunes (a)*, A. Ramalho (a) and L.M. Vilhena (a)

a CEMUC, Mechanical Engineering Department, University of Coimbra, Portugal

* [email protected]

Organic friction materials for brake linings, namely brake pads are polymer matrix

composites usually containing numerous macroscopic as well as microscopic

constituents such as filamentary reinforcements, solid lubricants, abrasives and

fillers. Their main objective of the these composite system are that a constant and

stable coefficient of friction (COF) is provided irrespective of environmental

conditions such as pressure, sliding velocity, temperature, humidity etc. Brake pads

performance should be maintained over a wide range of stress conditions. Although

the wear of the brake pad is inevitable, it should be minimized as far as possible.

While cast iron has been the dominant material for brake discs, brake pad materials

are constantly evolving into more complex composites.

The main objectives of the present work is to characterize the physical and the

tribological behavior of four commercial braking pads material formulations. Friction

and wear mechanisms and tribological behavior are analyzed in relation with the

composite microstructure as well as material mechanical properties. Considering the

service conditions of this components, the effect of temperature on the properties

was analyzed and discussed.

For all four compositions the studied factors are normal pressure and sliding speed,

considering one braking-test protocol designed with temperature and friction load

data acquisition. A double pad-on-disc tribological test configuration was used to

determine tribological properties of brake pad for heavy vehicles commercial. Three

wear tests via increased severity of rubbing conditions for a constant braking

distance.

Tribological behavior depends with formulation/composition and mechanical

properties. Temperature and COF show similar trends. For the friction mechanism: at

lower conditions, a stable friction film was generated on the surface of the brake pad,

providing excellent friction stability with less wear, while for higher conditions (sliding

speed and normal load) pads presented higher wear different wear mechanisms.

A morphological observation was done through the use of SEM. Wear rates, friction

coefficients and surface morphology are highly affected by contact temperature, pad

composition, normal load and sliding speed.

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Tribological behavior of functionalized 1-2 Layered graphene/UHMWPE composites

F.J. Pascual (a)*, L. Quiles (b), P. Castell (b) and J.A. Puertolas (a)

a Instituto de Investigación en Ingeniería de Aragón, I3A, Universidad de Zaragoza, E-50018, Zaragoza, Spain

b AITIIP Technological Center, E-50720, Zaragoza, Spain

* e-mail of Corresponding Author: [email protected]

Nowadays the Ultra High Molecular Weight Polyethylene is considered the cornerstone of the total knee and hip replacements because of its outstanding mechanical and tribological properties [1]. Specially, Highly Crosslinked UHMWPEs show the lowest wear rates while articulating to Co-Cr and ceramic counterparts. Nevertheless, the undesired oxidation of these polymers should be avoided through thermal stabilization treatments or the addition of antioxidants and free radical scavengers, such as carbon nanotubes [2].

In order to improve both mechanical and tribological properties, the addition of functionalized and pristine 1-2 layered graphene has been intended, considering the work made by Tai et al. with graphe oxide nanosheets [3]

All the composites were prepared by a high energy ball milling process followed by a thermo-mechanical consolidation process. The 1-2 layered graphene was provided by Avanzare (Spain) and in-house PEO-PE functionalization was performed prior to the mixing process.

Tribological characterization was made by ball-on-disk testing in two ways. Firstly, we recorded the friction coefficients from the testing device and then, the wear factors from the worn area was obtained through confocal microscopy.

Mechanical characterization was made by near-static uniaxial tensile test according to ASTM D638M and microstructural information was performed indirectly by DSC.

From the wear test, the graphene content and the wear factor has proved to be non-dependent for the selected concentrations, specially for the functionalized samples. On the other hand, the friction coefficients were lower in the functionalized samples studied.

Mechanical properties remain unchanged for the lower concentration of additives, while higher additions implied a decrease in mechanical performance.

References:

[1] S.M. Kurtz. The UHMWPE handbook, Academic Press, New York, USA, 2009

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[2] M.J. Martínez et al. Multi-walled carbon nanotubes acting as free radical scavengers in gamma-irradiated ultrahigh molecular weight polyethylene composites. Carbon 50 (2012) pp. 2442-2452.

[3] Z. Tai et al. Tribological Behavior of UHMWPE Reinforced with Graphene Oxide Nanosheets. Tribology Letters 46 (2012) pp. 55–63.

32


Wear behavior of cryogenically treated AISI 420 martensiticstainless steel

G. Prieto (a, b)*, W. R. Tuckart (a, b)

a Grupo de Tribología, Universidad Nacional del Sur. Bahía Blanca, Buenos Aires.Argentina

b Consejo Nacional de Investigaciones Científicas y Técnicas, Argentina.

* [email protected]

Cryogenic treatments have been employed over the last three decades in both tooland high-alloy steels to improve wear resistance, mainly through the transformationof retained austenite and the precipitation of fine carbides [1]. In this work the wearbehavior of cryogenically treated, low-carbon AISI 420 martensitic stainless steelspecimens has been studied with respect to that of conventionally heat treated ones.

The tribological properties of the materials were assessed by means of ball-on-disktests, under a range of applied normal loads, under a paraffinic aditive-free vaselinebath. The disks were made of AISI 420 stainless steel subjected to two different heattreatments, namely, quenched and annealed (CHT), and quenched, soaked in liquidnitrogen for 2 h and annealed (DCT). A 5 mm carbide tungsten ball was used as thecounterbody. Wear behavior has been characterized by wear volume, frictioncoefficient measurements and analyses of worn surfaces, wear debris andsubsurfaces. It was found that the wear resistance of cryogenically treatedspecimens showed increases ranging from 33% to 46% in comparison to theconventionally treated ones.

The cryogenic treatment of AISI 420 stainless steel decreases the average carbidesize and produces a more homogeneous spatial distribution of them [2]. Thesesmaller carbides are related to a lower stress concentration effect, therefore to areduced amount of strain accumulation and consequently, less sub-superficialcracking and delamination.

References:

[1] D. Das, A.K. Dutta, K. K. Ray, Sub-zero treatments of AISI D2 steel: Part II. Wear behavior, Materials Science and Engineering A, 527(9) (2010) 2194–2206.

[2] G. Prieto, J. E. Perez Ipiña, W. R. Tuckart, Cryogenic treatments on AISI 420 stainless steel: Microstructure and mechanical properties, Materials Science and Engineering A, 605 (2014) 236–243.

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Tribological study of the AISI316L/Sapphire contact with

self-lubricating films of protic ionic liquids

T. Espinosa-Rodríguez*, J. Sanes-Molina and M.D. Bermúdez-Olivares

Grupo de Ciencia de Materiales e Ingeniería Metalúrgica, Universidad Politécnica de Cartagena, Cartagena, Spain

* [email protected]

Ionic liquids have shown an outstanding performance as lubricants in different contacts. Protic ammonium carboxylate ionic liquids (PILs) both neat and as additives in water are being studied as friction-reducing and wear prevention lubricants, in stainless steel-sapphire contacts.

When a PIL was used as additive in water, the high temperature reached at the sliding contact produced the evaporation of water and the formation of a low friction PIL boundary layer [1].

In the present study, the formation of the PIL boundary layer on AISI316L stainless steel under static conditions is described and its lubricating performance against sapphire balls has been studied. The effect of relative humidity has been studied using a vacuum chamber.

The results described in the present study show a good tribological performance of these thin surface films, in pin-on-disc tests, reducing the running-in period of high friction coefficient, preventing wear and reducing the volume of lubricant with respect to the results obtained when water+1%PIL and neat PIL are used as lubricants.

References:

[1] T. Espinosa, M. Jimenez, J. Sanes, A. E. Jimenez, M. Iglesias, M. D. Bermudez, Ultra-Low Friction with a Protic Ionic Liquid Boundary Film at the Water-Lubricated Sapphire–Stainless Steel Interface, Tribol. Lett., 53(2014)1-9.

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34



Modelling and simulation/Tribocorrosion. Chair: Dr. Juan Carlos Sánchez López

35


Efficiency prediction on a 2.5 MW wind turbine gearbox

Carlos Fernandes (a)*, Maroua Hammami (b), Ramiro Martins (a) andJorge H. O. Seabra (c)

(a) INEGI, Universidade do Porto, Campus FEUP, Rua Dr. Roberto Frias 400,

4200-465 Porto, Portugal

(b) Laboratory of Mechanical, Modelling and Manufacturing, National School ofEngineers of Sfax, University of Sfax, Tunisia

(c) FEUP, Universidade do Porto, Rua Dr. Roberto Frias s/n, 4200-465 Porto,Portugal

* [email protected]

In previous works [1, 2], power loss measurements of different rolling bearing andgear geometries lubricated with different wind turbine gear oils were presented. Theexperimental results allowed to determine the coefficient of friction of rolling bearingand gears under similar conditions to that observed in a wind turbine gearbox.

A 2.5 MW wind turbine gearbox design was chosen to perform a power losssimulation. The power loss model presented [1, 2] was used to predict the efficiencyof the 2.5 MW wind turbine gearbox when lubricated by a mineral, a PAO and a PAGwind turbine gear oil. In a second phase, the gear tooth geometry of the wholegearbox were changed in order to improve the gearbox efficiency.

The calculations showed that the gearbox efficiency can be improved by modifyingthe oil formulation and/or modifying the tooth geometry.

References:

[1] C.M.C.G. Fernandes and P.M.T. Marques and R.C. Martins and J.H.O. Seabra,Gearbox power loss. Part I: Losses in rolling bearings, Tribology International, Inpress.

[2] C.M.C.G. Fernandes and P.M.T. Marques and R.C. Martins and J.H.O. Seabra,Gearbox power loss. Part II: Friction losses in gears, Tribology International, In press.

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Influence of grease formulation on rolling bearings friction torque

David Gonçalves (a)*, Samuel Pinho (b), Beatriz Graça (a), Armando Campos (c), Jorge H. O. Seabra (b)

a INEGI, Universidade do Porto, Faculdade de Engenharia, Porto, Portugal

b FEUP, Universidade do Porto, Faculdade de Engenharia, Porto, Portugal

c ISEP-IPP, Instituto Superior de Engenharia do Instituto Politécnico do Porto

* [email protected]

About 90% of all the rolling bearings are grease lubricated [1]. Despite this fact, there is very little work on the grease lubrication mechanisms which rule the film thickness formation and friction torque.

In this work a series of experimental tests were performed in thrust ball bearings lubricated with polymer greases at constant temperature and load, varying the entrainment speed. The tested greases were formulated with the same base oil (PAO) but different thickener content (polypropylene). A typical lithium thickened grease was also tested as benchmark.

The friction torque of thrust ball bearings lubricated with grease was measured in a rolling bearing test rig and the coefficients of friction under boundary and full film lubrication were numerically calculated through the approximation of the SKF friction torque model [2] to the experimental measurements.

Stribeck curves were constructed from the numerical results of coefficient of friction and discussed regarding the greases’ formulation and its influence on the friction torque of rolling bearings.

References:

[1] P. Lugt, Grease Lubrication in Rolling Bearings, Tribology Series, Wiley, 2013.

[2] SKF General Catalogue 6000EN (November 2005).

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Gear Scuffing: Power dissipation and mass temperature

J. Castro (a)* and J. Seabra (b)

a Departamento de Engenharia Mecânica, Instituto Superior de Engenharia, InstitutoPolitécnico do Porto, Portugal a Affiliation (Arial 12 pt, centered)

b Departamento de Engenharia Mecânica e Gestão Industrial, Faculdade deEngenharia da Universidade do Porto, Portugal

* [email protected]

Experimental gear scuffing results were obtained in the FZG test rig for wide rangesof the applied torque, tangential speed, base oil viscosity and bath oil temperature,and for FZG type A and type C gears.

For restricted and particular operating conditions all scuffing criteria seem to be valid,however no one seemed appropriated for the wide ranges of operating conditionsconsidered. A preliminary analysis of the experimental results shows that the oil bathtemperature and the friction coefficient between gear teeth have a very significantinfluence on the scuffing load carrying capacity of the FZG gears.

A scuffing criterion for FZG gears (FZG: Gear Research Centre at TechnicalUniversity Munich) lubricated with base oils is proposed based on several differentcriteria: the traditional PVT scuffing criteria (Alman criteria) is adequate when the aimis to compare the performance of different gear geometries; the FPI (Friction PowerIntensity) scuffing criteria, together with the friction coefficient developed, is adequateto evaluate the influence of the torque (or contact pressure) and of the tangentialvelocity in scuffing [1, 2];. The criteria proposed adopted the integral concept fromintegral temperature criteria applied to FPI, resulting in critical oil bath temperaturesor gear mass temperatures, above which the lubricant has no longer the ability togenerate an hydrodynamic film and scuffing may occur for non-severe conditions, inthe case of base oils without anti-wear or extreme pressure additives. Anotherimportant aspect is the zone where the scuffing occur is also predicted by thiscriteria.

References:

[1] J. Castro and J. Seabra, Coefficient of friction in mixed film lubrication: Gearversus twin-disc, Proc. Instn of Mech. Engrs, Part J: Journal of EngeneeringTribology, 2007, 221 (J3), 399-411, doi:10.1243/13506501.JET256.

[2] J. Castro e J. Seabra, Global and local analysis of gear scuffing tests using amixed film lubrication model, Tribology International, Vol. 41/4 (2008), pp. 244-255,doi:10.1016/j.triboint.2007.07.005.

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STUDY ON THE WEAR AND ROLLING CONTACT FATIGUE

BEHAVIOR OF RAIL STEEL GRADES BY USING A TWIN DISC

LABORATORY EQUIPMENT

M. Panera (a)*, P. García (a), D. Álvarez (a), H. Pérez (a), J. Belzunce (a), J. Arancón (b), D. Carrascal (b)

a ITMA Materials Technology, Parque Empresarial Principado de Asturias, 33417 Avilés

b ArcelorMittal, Global R&D Asturias

*email: m.panera @itma.es

Rail wear and fracture due to Rolling Contact Fatigue (RCF) are serious problems on railways worldwide. Both phenomena are due to repeated wheel contacts applying normal stress and tangential traction which, combined, are typically above the yield stress of material [1].

This work analyzes the wear and the RCF behavior of different rail steel grades versus a railway wheel steel in a twin-disc laboratory scale equipment and compares the obtained results with those obtained in full scale testing machine [2].

For this purpose, a twin-disc laboratory scale equipment was designed and put into service [1], in order to carry out quick and inexpensive tests applying the contact pressures appearing in the railway.

Different steel grades have been tested by modifying the test conditions and analyzing the influence of the applied load and the sliding rate on the wear and RCF behavior of these materials.

At the end of the tests, the rail test specimens have been analyzed by the determination of mass loss and metallographic characterization. The nature, shape and size of the cracks have been analyzed and compared to those obtained in the full scale tests carried out with the same materials.

The obtained results supports that the proposed laboratory tests are able to predict the behavior of the different grades in rail-wheel systems in a quick and easy way.

[1] D. I. Fletcher, J. H. Beynon “Development of a Machine closely Controlled Rolling Contact Fatigue and Wear Testing”, Journal of Testing and Evaluation, JTEVA, Vol. 20, No. 4, July 2000, pp 267 -275

[2] P. García, M. Panera, J. Belzunce, E. Fidalgo, J. Arancón¸ ” Study on the rolling contact fatigue behavior of rail steel grades”, VIII Iberian Conference on Tribology (IBERTRIB 2015).

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Analysis of valve and valve seat insert damage morphology

observed after different engine tests.

Alexander Zuleta Durango (a)*, Felipe Mazuco (a), Amilton Sinatora (a)and Deniol K. Tanaka (a)

(a) Surface Phenomena Laboratory, Mechanical Engineering Department, Universityof Sao Paulo, Av. Prof. Mello Moraes 2231, ZIP 05508-900, Sao Paulo, SP, Brazil

* [email protected]

This paper presents visual examination results and topographic analysis of two 8-valves engines intake and exhaust valves in order to characterize wear damages aspart of the “FAPESP – Desafios tribológicos em motores Flex-Fuel – TRIBOFLEX”

project. One of the engines was tested in dynamometer through thermal shock test,operated from idle to full load regime. Another engine was tested using conventionalvehicle in injection system test. The terminology used to describe observed damageswas not lined up with the commonly used designations in the literature, to avoidpreconceived ideas of the damage. The damage was documented using scanningelectron microscopy (SEM) with an energy-dispersive X-ray spectroscopy (EDS) andphotographically using optical microscopy. Many damages were observed in both:intake and exhaust valves of both engines, although some damages, such asoxidation, was observed only in the exhaust valves. The damages characterized as:presence of deposits, polishing and oxidation were observed. Through detaileddescription and documentation of valves damages it is expected to contribute to thecharacterization of valves wear morphology by the automotive industry.

References:

[1] A. Sinatora and D.K. Tanaka, Analysis of engine valves damage morphologyobserved after engine dynamometer test, SAE International, 2014-36-0305.

[2] Y. Wang, Introduction to Engine Valvetrains, SAE International, 2007.

[3] Mahle GmbH, Valve train System and Components, 2013.

[4] R. Lewis and R.S. Dwyer-Joyce, Automotive Engine Valve Recession. Suffolk,UK: Professional Engineering, 2002, 137 pp.

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Thursday, 18th June SESSION B3 Biotribology.

Chair: Dr. Patricia Iglesias Victoria

41


Abrasive and sliding wear of resin composites for dental

restorations

A.C. Bentes (a, b), K. Reis (c), J.C.M. Souza (d) and J.R. Gomes (a, b)*

a Universidade do Minho, Departamento de Engenharia Mecânica, Guimarães,Portugal

b MEMS R&D Centre, Guimarães, Portugal

c Medicina Dentária, Universidade Fernando Pessoa, Porto, Portugal

d School of Dentistry, Universidade Federal de Santa Catarina (UFSC),Florianópolis / SC Brasil

* [email protected]

The development of resin composites as dental restoration materials came throughthe need for materials that mimic natural tooth structures. However, wear of thesecomposites still remains as a major clinical problem. Through various studiesconducted, it was found that the wear resistance of such materials mainly dependson aspects related with the fillers, in particular their size and distribution as well as itsvolume percentage.

The main objective of this work was the tribological characterization of fourcommercial resin composites for direct dental restoration by the evaluation of theirresistance to abrasive and sliding wear as well as by the identification of thedominant wear mechanisms. Compression tests have allowed determine thecompressive strength of the composites as well as their elastic modulus. Micro-abrasion tests were performed using slurry based on a commercial whiteningtoothpaste as abrasive compound, with a normal applied load of 3 N and lasting 300revolutions. The tribological characterization was complemented by reciprocatingsliding wear tests in a ball-on-plate geometry in presence of artificial saliva at 37° C.Alumina was used as counterface and these tests were carried out at constantfrequency of 1 Hz and normal applied load of 25 N.

The wear volume was evaluated for the different groups of composites andcorrelated with their mechanical properties and composition in terms of size andvolume percentage of fillers. The determinant role of fillers on the tribologicalbehaviour of composites was confirmed both as a consequence of the abrasiveaction of a toothpaste or due to the sliding against a hard ceramic surface.Composites with higher volume fraction of reinforcing particles (82% wt.) combinedwith particles with higher size presented the best tribological response. The dominantwear mechanisms consisted in fine scale abrasion for micro-abrasion tests andsurface fatigue for reciprocating sliding tests.

B3.1

42


Development of the microbiological population in water miscible

metal working fluids

Benedikt Seidel (a)*, Anne-Gönke Huesmann-Cordes (a) and AndreasRabenstein (a)

a Foundation Institute of Materials Science, Badgasteiner Str. 3, 28359 Bremen,Germany

* [email protected]

Keywords: Lubrication, cutting fluids, microbiological deterioration

The deterioration of metal working fluids (MWF) due to the microbial colonization anddegradation is a considerable economic factor in the metal working industry.Microorganisms (MO) are able to metabolize almost all components of MWF andthus leading to a loss of its function by the reduction or depletion of additives.Microbial growth cannot be avoided completely, although various methods exist toreduce the bacterial load in MWF. This paper presents a study on the colonization ofMWF by bacteria and fungi in an industrial environment. The condition of coolinglubricants has been periodically examined based on biological and chemicalmethods. The level of the total bacterial load in the lubricant is considered as well asthe composition of the species community and its development over the evaluationperiod. With regard to the increasing relevance of environment friendly processes, aconventional mineral oil based MWF has been compared to a product based onrenewable resources.

B3.2

43


Friction of Human skin against different hospital fabrics

L.M. Vilhena (a)*, P.V. Antunes (a), A. Ramalho (a)

(a) CEMUC, Department of Mechanical Engineering, University of Coimbra, Rua Luís

Reis Santos, 3030-788 Coimbra, Portugal

* [email protected]

Knowledge on tribology of human skin is essential to improve and optimise surfacesand materials in contact with the skin, as well in the design process of consumerproducts. Besides that, friction between the human skin and textiles are criticalfactors in the formation of skin injuries (irritations, abrasions, decubitus and blisters),which are caused if the loads and shear forces are high enough and/or over longperiods of time. This factor is of particular importance in bedridden patients sincethey are not moving about or are confined to wheelchairs (and may be aggravated byincontinence or perspiration). Decubitus ulcers are one of the most frequentlyreported iatrogenic injuries in developed countries. The risk of developing decubitusulcers can be predicted by using the “Braden Scale for Predicting Pressure Ulcer

Risk” that was developed in 1987 [1], and contains 6 areas of risk (cognitive-perceptual, immobility, inactivity, moisture, nutrition, friction/shear), although thereare limitations to the use of such tools. The coefficient of friction of textiles againstskin is mainly influenced by: the nature of the textile, skin moisture content andambient humidity. This study will investigate how skin friction (different anatomicalregions) varies, rubbing against different type of contacting materials (i.e. syntheticand natural fabrics) under different contact conditions and their relation with thedecubitus ulcers formation. The results will be compared with a reference hospitalfabric.

References:

[1] Kozier, Barbara, Glenora Erb, Shirlee Snyder, and Audrey Berman. Fundamentalsof Nursing: Concepts, Process, and Practice. 8th ed. Upper Saddle Riveer, NJ:Pearson Education, 2008. 905-907. Print.

B3.3

44


Biofilm influence on the pair tribological wear tooth-zirconia

Carla Carneiro (a, b) §, Joana Sousa (a), Célio Figueiredo-Pina (a, c) §*a Escola Superior de Tecnologia de Setúbal, Instituto Politécnico de Setúbal, Campus

do IPS, 2910-761 Setúbal, Portugal

b REQUIMTE/Centro de Química Fina e Biotecnologia, Faculdade de Ciências e Tecnologia Universidade Nova de Lisboa, 2829-516 Caparica, Portugal

c CeFEMA, Instituto Superior Técnico, UTL; CeFEMA, Instituto Superior Técnico,UTL; Rua Rovisco Pais, 1049-001, Lisboa, Portugal

§ Both of these authors contributed equally to this work

* [email protected]

Tooth wear is an inevitable process due to chewing conditions, and the developmentof materials for dental restoration, it is necessary to their tribological evaluation. Oneof the requirements of these materials is exhibiting a low wear and avoid abnormalwear of the antagonist teeth. The wear tests are usually carried out in distilled wateror artificial saliva without taking into account the existence of microorganisms.However the oral cavity has a characteristic microbiota, since it is warm, moist andrich in nutrients conducive to complex biofilms formation that colonize the surfaces ofthis cavity.

This study aimed to evaluate the effect of the presence of bacteria in the tribologicalpair wear zirconia/tooth. Streptococcus salivarius (S. salivarius) was the selectedbacteria given its importance and prevalence in the oral cavity, relative to otherStreptococcus strains. Its growth profile was studied in BHI media, artificial saliva,with and without a meal representative supplement, with variant pH in order todetermine the optimum growth conditions. The tests, pin-on-plate type, where thepins were cusps of molars and premolars, and the plates zircónica were performed ina comparative way using: artificial saliva, artificial saliva with glucose and withglucose and S. salivarius, at a temperature of 37 °C and pH 7. The worn surfaceswere analyzed by scanning electron microscopy.

Results show that both, the friction coefficient and the wear, are conditioned by thepresence of bacteria. The tooth wear results show a reduction of 50% when S.

salivarius is present but no wear was detected on the zirconia surface.

It can be concluded that the existence of biofilms in the zirconia/tooth interfaceaffects the tribological results leading to a decrease in friction coefficient and wear ofthe tooth.

B3.4

45



The tribological behaviour of a newly developed water absorbable Skin Equivalent compared to isolated human skin during sliding

M. Morales-Hurtado1, X. Zeng1, M. Peppelman2, P. van Erp2 and E. van der Heide1,3

1Surface Technology and Tribology Group, University of Twente,

Drienerlolaan 5, 7522 NB Enschede, The Netherlands

2Medical Centre, Dermatology department, Radboud University of Nijmegen,

Geert Grooteplein-Zuid 10, 6525 GA, Nijmegen, The Netherlands

3TNO PO Box 6235, 5600 HE

Eindhoven, The Netherlands

[email protected]

This paper focusses on the frictional response of a new 2 Layer Model (2LM), developed to mimic the human skin performance during testing of consumer products interactions with skin. The 2LM, designed to interact with water, is composed of a bottom layer of PVA hydrogel reinforced with cellulose micro fibers and a top coating of Epidermal Skin Equivalent (ESE). The tribological results of the model were compared to the frictional response of isolated human skin. Furthermore, the response was compared to commercially available substitutes including Lorica, PDMS, PVA hydrogel reinforced with cellulose and silicone. The tribological performance of these materials was evaluated against five different counter surfaces: PA6.6, PET, ball bearing steel AISI 52100, stainless steel AISI 316 and NBR. The measurements were carried out at two environmental conditions: moderate temperature and humidity conditions (25 °C and 50% relative humidity) and high temperature and humidity conditions (37 °C and 80% relative humidity). The applied force corresponded to a range of pressures of 140-170 kPa and the experiments were conducted at two different velocities of 50 mm/s and 250 mm/s.

The human skin samples, obtained from healthy people after surgical non-related problems with skin, were provided by the University Medical Centre Nijmegen (The Netherlands). Their tribological behaviour was studied at normal conditions and their surface was examined by confocal microscopy to determine the changes after the frictional tests. Additionally, histological measurements were carried out and the images showed the damage of the outermost layer of skin (Stratum Corneum) after the performed tests.

The tribological results confirmed the better agreement of the 2LM with the tribological performance of the isolated human skin, compared to the tribological results obtained with the commercially available substitutes. Besides, the wear of the 2 layer model and the human skin tissue after the friction tests showed to be similar based on a qualitatively assessment of the track width by confocal measurements.

B3.5

46



Micro and Nanotribology. Chair: Dr. Manuel Belmonte Cabanillas

47


Wear model for reciprocating ball-on-flat wear tests

Esteves, M.a*, Ramalho, A.a

a CEMUC, University of Coimbra, Coimbra, Portugal

* e-mail of Corresponding Author: [email protected]

Nowadays, a reliable prediction for the outcome result of a working process wearimplication is very difficult to obtain during the project phase of said components.Regarding said situation, a wear model suitable for sliding wear was designed,allowing to forecast the volume loss on the both sliding surfaces.

The current model was created especially to be applied on ball on flat contact. TheHertzian normal contact pressure and a friction stress field are used to determine theresulting contact stresses field leading to analyze locally the wear process. Thequantification and matching wear amount can be established using a model based onthe energy dissipated by friction or alternatively a model based on the normalpressure.

An experimental validation study was produced for a pair of materials commonlyused in mechanical applications, regarding a chromium sphere (AISI 52100) againsta gray cast iron flat specimen (GJL 200) for a normal load between 5 N and 12 N, 1Hz frequency and a range between 5500 and 10000 cycles.

The initial results present a very good correlation between experimental results andpredicted values from the wear model, with special attention to a high dependency onwear rate values used in the model. The resulting wear as compared consideringboth the local wear depth and the wear volume of experimental tests with theforecasted values.

The shown dependency of wear rates was to be expected since the process isdependent on the energy dissipated by friction. The scar morphology should beimproved along with a more continuous contact geometry iteration.

A4.1

48


Temperature And Pressure Distribution Analysis On Deformable

Short Hydrodynamic Bearings

Luigi Carvalho Greco, Prof. Dr. Roberto Martins de Souza, Prof. Dr.Rodrigo Lima Stoeterau

Polytechnic School of the University of São Paulo

* [email protected], [email protected], [email protected]

This paper presents a discussion on the study of thermal and elastic effects resultingfrom support bearings. It was proposed a mathematical model based on the shortbearings equations within the cavitation region, using the principle of mass continuity.Then, equations are deduced from the Reynolds ones [1] and energy equations,applying a modification to the Ocvirk’s solution [2]. All the equations are numerically

solved by the Backward Finite Difference Method. In addition to the treatment of fluidmechanics, this paper includes thermal analysis on bearings discussed by [3]. AFinite Element Model was used to calculate the deformation of the structure, for aspecific geometry and an evaluation of the variation of the pressure field is conductedto determine how this difference affects other fluid properties. Finally, an overallanalysis was conducted within the full model to predict the short bearing properties.Comparing mean results presented by [4] and calculated ones provides a differenceof 2.33% between the maximum pressure, and about 1.78% for eccentricity ratio, fora length-diameter bearing ratio (LDR) of ½. These results demonstrate that themodel presents a relevant and accurate approximation for experimental data,reducing the time for calculate some initial properties or making qualitative decisionsabout its operation.

References:

[1] O. Reynolds. The Theory of Lubrication and its application to Mr. BeauchmapTower´s experiments, including an experimental determination of viscosity of olive oil.Philosophical Transactions of The Royal Society, 1886.

[2] W. Ocvirk. Short Bearing Approximation for Full Journal Bearings. NACA TN2808, 1952.

[3] R. Boncompain, M. Fillon and J. Frene. Analysis of thermal effects inhydrodynamic bearings. ASME/ASLE Joint Lubrication Conference, Atlanta, 85-Trib-21, 1985.

[4] J. Frene et al. Hydrodynamic Lubrication: Bearings and Thrust Bearings.Amsterdam. Elsevier. 1997.

A4.2

49


Study of creep function determination of two amorphous polymers

by indentation technique

M. A. Garrido (a)* and J. Rodríguez (a)

a DIMME – Durabilidad e Integridad Mecánica de Materiales Estructurales.

Escuela Superior de Ciencias Experimentales y Tecnología.

Universidad Rey Juan Carlos. c/Tulipán s/n, Móstoles, Madrid, Spain.

* [email protected]

A common practice to determine the mechanisms that govern the wear process in a

material consist of trying to correlate the wear rate to the mechanical properties of

the material at the surface. The instrumented indentation has become a suitable

technique for characterization of thin films or coatings. This technique may be applied

to all types of materials: metals, ceramics, polymers and composites; however each

type of material has a specific behavior against penetration by an indenter.

Consequently, corrections to the equations that govern the technique or specific

treatment of the data obtained from the tests should be done. In this work problems

associated with the mechanical characterization by instrumented indentation of two

amorphous polymeric materials: PMMA and PC, have been studied. Additionally, the

creep function of each material has been obtained from the indentation data.

References:

[1] E.H. Lee and J.R.M. Radok, The contact problem for viscoelastic bodies, Journal

of Applied Mechanics, 27 (1960) 438

[2] H. Lu, B. Wang, J. Ma, G. Huang and H. Viswanathan, Measurement of Creep

Compliance of Solid Polymers by Nanoindentation, Mechanics of Time-Dependent

Materials 7 (2003) 189

[3] L. Cheng, X. Xia, L.E. Scriven and W.W. Gerberich, Spherical-tip indentation of

viscoelastic material, Mechanics of Materials 37 (2005) 213

A4.3

50


STUDY ON THE ROLLING CONTACT FATIGUE BEHAVIOR OF RAIL STEEL GRADES

P. García (a)*, M. Panera (a), J. Belzunce (a), E. Fidalgo (b), J. Arancón (c)

a ITMA Materials Technology, Parque Empresarial Principado de Asturias, Avilés

b ICube, Parque Científico Tecnológico de Gijón

c ArcelorMittal, Global R&D Asturias

(*) [email protected]

The continuing increase of axle loads, train frequencies and train speeds, both in passenger service and freight operations, are causing a corresponding increase in the stresses on track and trains [1]. Rolling Contact Fatigue (RCF) is one of the various forms of rail failure and it has important impact on rail maintenance and life-cycle matters [2].

This work analyses the wheel-rail interaction in terms of rolling contact fatigue (RCF). For this purpose, a full scale testing machine was designed and built in order to apply the loads and boundary conditions appearing in the railway (up to 30 tons per wheel, application of lateral load in bends, inclination, angle of attack, dust, water…)

Ten tests were performed with different load conditions and rail grades and RCF cracks were generated after 50000 to 200000 cycles. The occurrence of cracks was determined by magnetic particle inspection at regular intervals in the course of the tests. When the non-destructive inspection showed the existence of cracks, the test was stopped and the rail cut longitudinally and transversally to perform a metallographic analysis in order to know the nature, growth direction, shape and size of the cracks.

The cracks generated in the laboratory tests were identical to those seen in RCF affected railways [3] and significant variations were found in the behavior of the different rail grades. The proposed test was able to simulate the damage produced in rails by RCF and allows comparing the fatigue behavior of different rail grades under very well controlled conditions.

[1] Pointer, P., The impact of wear and RCF on rail – a pragmatic approach, ZEVrail, 2008

[2] Rolling contact fatigue on the British railway system: treatment, Wear 258, 2005.

[3] Innotrack project, deliverable D4.3.7: Innovative laboratory tests for rail steels, 2009.

A4.4

51


Thursday, 18th June SESSION B4 Biotribology.

Chair: Prof. Dr. José R. Gomes

52


Evaluation of tribological properties of new alumina-zirconia ceramics for dental restorations

Célio Figueiredo-Pinaa,b*; Micaela Rodriguesa, Mafalda Guedesa,b

a Department of Mechanical Engineering, Setúbal School of Technology, Instituto Politécnico de Setúbal, Setúbal, Portugal.

b CeFEMA, Instituto Superior Técnico, ULisboa, Lisboa, Portugal.

* [email protected]

There is great interest in the use of ceramics as dental restoration materials, due to the similar optical properties to natural teeth in terms of colour and translucency. These materials have also shown adequate mechanical and tribological properties to withstand the demanding environment of the oral cavity. However a main concern is the possibility of excessive wear and/or stress concentration caused by mechanical mismatching between the dental material and teeth. The restoration material should not wear out easily, leading to abnormal enamel wear of the antagonist tooth.

In the present work several ceramic composites were developed in the Al2O3-Zr2O system, using ZrO2 submicron or nano-particles. The materials were produced via the powder route, by slip casting, sintered and polished. The attained surfaces were characterized by scanning electron microscopy and profilometry; hydrophilicity was evaluated using the sessile drop method. To evaluate the wear resistance reciprocating pin-on-plate tests were carried out at a frequency of 1 Hz, under applied load of 2 N for 6 h, in artificial saliva at 37 °C. The produced materials were used as plates; cusps of molar and pre-molar human teeth were used as pins. Commercial zirconia was used as reference material.

The produced materials present high densification, although SEM observation reveals some porosity. Composites based on nano-particles were more hydrophilic than these obtained with submicron particles. Wear tests results showed little ceramic wear and cusps wear. The highest tooth wear was obtained against commercial zirconia plate, however the friction coefficient obtained with this material was the lowest. The lower tooth wear was obtained for plates with 100% alumina.

Overall, attained results suggest that tooth wear is influenced by the roughness of the opposing ceramic surfaces.

B4.1

53


BIOTRIBOLOGY STUDY FOR DETERMINING THE INFLUENCE OF SURFACE MODIFICATION IN PEEK AND UHMWPE IN THE

REDUCTION OF PARTICLES RELEASING FOR KNEE PROSTHESIS APPLICATION

Cristina Díaz (a) *, Gonzalo Fuentes (a) a Asociación de la Industria Navarra (AIN), Ingeniería de Superficies, Pamplona,

Spain

* e-mail��[email protected]��

The formation and development of wear are now widely accepted as a major concern in the long term survivor using knee prosthesis. Usual materials for tibial part of the knee prosthesis are UHMWPE and PEEK. The surface of these materials plays an important role in the particles releasing and in wear rate. Therefore, UHMWPE and PEEK polymers tibial components are susceptible to abrasion from harder counterfaces which could introduce third body debris, as a part of bone, introducing the deterioration of their surface and finally the faillure of the articular prosthesis.

This work proposes to introduce a surface modification by ion implantation of combination of several elements such as He, O and N in these polymer materials in order to give them better mechanical resistant, reduce their wear rate of the prosthesis and as a consequence the total released particles in metal-on-polymer prosthesis.

Studies of roughtness, hardness and biotribology in serum bovine at 37ºC have been carried out in order to compare modified UHMWPE and modified PEEK against CoCrMo alloy and Al2O3 ceramic material. After them, the serum was collected in order to analyze released particles by AFM and DLS techniques.

Results showed an interesting reduction in wear rate and released particles which will permit to plan the next step: carry out these same studies in real pieces.

B4.2

54


Wear and corrosion behaviour of CoCrMo biomedical alloy in presence of hydrogen peroxide

R. Catalá Carrión, J. Navarro Laboulais, A, Igual Muñoz*

Instituto de Seguridad Industrial, Radiofísica y Medioambiente, Universitat Politècnica de València, Spain

* [email protected].

Hydrogen Peroxide naturally appears in aerobic biological systems through the formation of superoxide free radical anion by metabolic reduction of molecular oxygen. Hydrogen peroxide is a strong oxidant and a source of free radicals, which effect on corrosion has been extensively studied on titanium and its alloys [1]. However, the consequences of the presence of H2O2 on the tribological response of biomaterials are scarce. The aim of this work is to study the electrochemical behaviour and the combined effect of wear and corrosion (tribocorrosion response) of a CoCrMo biomedical alloy in presence of H2O2.. For this, open circuit potential (OCP) measurements, potentiodynamic curves and potentiostatic tests in PBS with increasing hydrogen peroxide content (from 0.15 to 1.18 M) were carried out. Unidirectional pin-on-disk tribometer was used under electrochemically-controlled conditions (OCP and applied passive potential) to analyze the underlying tribocorrosion mechanisms.

Hydrogen peroxide, in the studied concentration range, increases the cathodic kinetic reactions and shifts the corrosion potentials towards the high-passive domain of the alloy, thus increasing the corrosion rate of the CoCr alloy when compared to the PBS solution. Under tribocorrosion conditions at OCP, a galvanic coupling between the worn (active) and unworn (passive) area is established, thus an OCP decay is observed at the onset of rubbing. In presence of H2O2, the OCP decay decreases as the H2O2 concentration increases due to the change in the cathodic kinetics in the unworn zone, however wear volume slightly increases with the oxidant presence in the solution. Wear mechanism in PBS shows an abrasive behaviour caused by the formation of third bodies while the presence of H2O2 produces smooth surfaces by chemical polishing.

References:

[1] C. Fonseca, M.A. Barbosa. Corrosion Science 43 (2001) 547.

B4.3

55


Tribocorrosion behaviour of mooring HSLA steel in synthetic seawater under bidirectional sliding

Ainara López (a)*, Raquel Bayón(a), José Luís Arana (b), Francesco Pagano(a), Amaya Igartua(a)

a IK4-Tekniker, Eibar, Spain

b Department of Metallurgical and Materials Engineering, University of Basque Country, Spain

*[email protected]

Abstract

The chains and accessories that compose mooring lines are subjected to several environmental attacks that accelerate their degradation. One important phenomenon is Tribocorrosion, since mooring lines are subjected to both high corrosion rates when immersed in the ocean and continuous wear due to the relative motion between components caused by the action of waves, wind and sea currents. In the present work, the tribocorrosion behaviour of mooring HSLA steel is studied. For this aim, bidirectional sliding tests have been performed in synthetic seawater, with varying conditions of anode-to-cathode area ratio and temperature. The resulting wear tracks have been analyzed by means of optical microscope, confocal microscope and Scanning Electron Microscopy/Energy-Dispersive X-ray Spectroscopy (SEM-EDS).

B4.4

56


Friday, 19th June SESSION A6

Case Studies/Characterization Techniques.Chair: Prof. Dr. Anna Neus Igual Muñoz

57


The effect of fuel dilution and oil aging of lubricants on the piston

ring/liner tribochemistry for HDVs using used cooking oil as a fuel

Ardian Morinaa, Chun Wanga* and Hu Lib aSchool of Mechanical Engineering, Institute of Functional Surfaces,

University of Leeds, Leeds, LS2 9JTbSchool of Chemical and Process Engineering, Energy Research Institute,

University of Leeds, Leeds, LS2 9JT

* [email protected]

Biofuel is increasingly used in road transport including heavy duty vehicles due tothe growing concern of global warming and energy supply security. However,lubricant oil contamination and oil ageing by biofuel due to continuous circulation ofthe lubricant and the burning of biofuel are challenges to engine performance [1].This paper reports on an experimental study of friction and wear performance of fullyformulated engine oils when a used cooking oil based biofuel was used as fuels- Thetest conditions were relevant to ring/liner interface of the engine cylinders.Experiments were conducted on a reciprocating tribometer Cameron Plint TE77using samples manufactured of grey cast iron and AISI 52100 steel. The tribologicalperformance of two types of fresh oils and their corresponding aged oils were carriedout under boundary lubrication conditions at different temperature. Wearmeasurements were carried out using the optical interferometry technique. Surfacecharacterisation was carried out using Raman spectroscopy and Atomic ForceMicroscopy (AFM). It was found that the aged oils gave much higher wear than thefresh oils. In this paper, the results obtained from wear scar analysis will bediscussed in detail to obtain the mechanisms by which the biofuel and ageing affectthe engine oil properties and consecutively friction and wear performance.

References:

[1] AMSOIL, Fuel Dilution Causes and Effects. (2004), available from:http://www.amsoil.com/techservicesbulletin/MotorOil/TSB%20MO%202004-07-02%20Fuel%20Dilution.pdf

A6.1

58

http://www.amsoil.com/techservicesbulletin/MotorOil/TSB%20MO%202004-07-02%20Fuel%20Dilution.pdf

http://www.amsoil.com/techservicesbulletin/MotorOil/TSB%20MO%202004-07-02%20Fuel%20Dilution.pdf


Mechanism of tribo-chemical reactions of ionic liquids on titanium alloys

Berriozabal, E. (a), Igartua, A. (a), A., Pagano F. (a), Cambra, J.F. (b), Minami, I. (c), Doerr, N.(d), Gabler, C. d),

a IK4-TEKNIKER, Parke Teknologikoa, C/ Ignacio Goenaga, 5, 20600 Eibar, Guipuzcoa, Spain

b Universidad Del País Vasco (UPV/EHU), School of Engineering, Alda. Urquijo, sn, 48013 Bilbao

c Luleå University of Technology, Division of Machine Elements, SE97187 Sweden

d AC2T research, Viktor Kaplan Straße 2, 2700 Wiener Neustadt

a) [email protected]

In this paper, the tribological, the tribo-chemical reaction mechanisms and desorption properties of three ionic liquids (ILs), [Bu3MeP][TF2N], [Bu3MeN][TF2N] and [Bu3MeP][ (MeO)2PO2], in contact with titanium and under vacuum conditions are studied with the CATRI © UHV Tribometer developed by IK4-TEKNIKER [1].

The two ILs containing the bis (trifluoromethane sulfonil)amide anion presented lower coefficient of friction compared to that having the dimethyl phosphate anion. The tribodesorption study revealed that it is required an induction period to decrease the friction coefficient. The end of this period is accelerated in the case of trifluoromethane ionic liquids by the CF3

+ release. Hence, the CF3+ reacts with the

titanium surface generating a titanium fluoride tribolayer that could act like a catalyst to generate the tribodesorption of ionic liquid cation fragments (CH3

+, C2H5+, C3H7

+, C4H9

+). The XPS analysis confirmed the generation of a boundary film, comprising of sulfide and inorganic fluoride, and being possibly the responsible of decreasing the friction coefficient. The [Bu3MeP][MeO)2PO2] ionic liquid required a long induction period, it did not form any tribolayer and no reduction of friction coefficient, yielding instead a high abrasion and adhesion mechanism. Thus, it can be concluded that bis(trifluoromethane sulfonyl)amide anion is more effective than dimethylphosphate in generating a surface protective film on the titanium surface under the selected test conditions and the testing methodology seems to be useful to understand the tribodesorption mechanism.

References:

[1] a) CATRI Machine © IK4-TEKNIKER. Patents PCT/ES2009/070635. PCT/ES2010/070273. b) R. Nevshupa, M. Conte, A. Igartua, E. Roman, JL. Segovia, " Ultrahigh vacuum system for advanced tribology studies: Design principles and applications", Tribology International, 86, p28-35, 2015, www.elsevier.com/locate/triboint

A6.2

59


A6.3Study of the isothermal oxidation treatments effect on the local

wear behaviour of Inconel 625 coatings deposited by laser cladding

D. Verdi (a)*, M. A. Garrido (a), C. Múnez (a) and P. Poza (a)

a DIMME – Durabilidad e Integridad Mecánica de Materiales Estructurales.

Escuela Superior de Ciencias Experimentales y Tecnología.

Universidad Rey Juan Carlos. c/Tulipán s/n, Móstoles, Madrid, Spain.

* [email protected]

Ni-based alloys, such as Inconel superalloys, are characterized by high strength,

excellent fabricability (including joining), and outstanding corrosion resistance.

However, their use is limited by their high cost. Recently, Ni based coatings are being

used on carbon steel components in order to increase their service life under

extreme conditions. Laser cladding deposition has emerged as an excellent method

for processing Ni based coatings. In this work, the evolution of the local wear

behaviour of Inconel 625 laser cladded coatings after high temperature isothermal

oxidation treatments have been investigated.

References:

[1] P. Poza, C.J. Múnez, M.A. Garrido-Maneiro, S. Vezzù, S. Rech and A. Trentin,

Mechanical properties of Inconel 625 cold-sprayed coatings after laser remelting.

Depth sensing indentation analysis, Surface and Coatings Technology, 243 (2014)

51

[2] G.L. Goswami, S. Kumar, R. Galun and B.L. Mordike, Laser cladding of Nickel

based carbide dispersion alloys for hardfacing applications. Lasers in Engineering 13

(2003) 35

[3] S.P. Wen, R.L. Zong, F. Zeng, Y. Gao and F. Pan, Investigation of the wear

behaviors of Ag/Cu multilayers by nanoscratch, Wear 265 (2008) 1808

[4] J.A. Greenwood, and J.B.P. Willamson, Contact of nominally flat rough surfaces,

Proceedings of the Royal Society of London A 295 (1966) 300

60


Wear resistant in-situ carbon nanotubes/silicon nitride nanocomposites with a high loading of nanotubes

Jesús González-Julián (a), Johannes Schneider (b) and Manuel Belmonte (c)*

aInstitute for Energy and Climate Research (IEK-1) Forschungszentrum Jülich, 52425 Jülich, Germany

bInstitute for Applied Materials, Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany

cInstitute of Ceramics and Glass (ICV-CSIC), Kelsen 5, 28049 Madrid, Spain

*[email protected]

High pressure gasoline direct injection (GDI) systems are able to considerably reduce both the fuel consumption and the harmful emissions, but the current metallic components should be replaced by new advanced materials with enhanced tribological properties. In a previous work, the benefits of using carbon nanotubes (CNTs) in the tribological properties of silicon nitride (Si3N4)-based nanocomposites simulating GDI operating conditions were pointed out [1]. However, new questions arise such as: can these properties be enhanced introducing larger CNTs contents? And, will it be possible to disperse them?

In the present work, highly homogenous CNTs/Si3N4 nanocomposites with high CNTs loadings (12 vol.%) were developed through the in-situ synthesis of CNTs on the ceramic powders, and further densification using the spark plasma sintering technique. For comparison purposes, similar materials were processed by the ex-situ method based on the mixing of nanotubes and ceramic powders in a solvent media. Isooctane lubricated reciprocating ball-on-plate tests were conducted at loads of 50-200 N, stroke length of 2.5 mm, frequency of 20 Hz, and sliding distance of 360 m.

In-situ nanocomposites exhibited an excellent tribological behaviour, being 87% and 65% more wear resistant than Si3N4 materials and ex-situ nanocomposites, respectively, and also leading to the lowest friction at high contact pressures. The higher nanotubes dispersion and better mechanical properties attained by the in-situ process were the keys for the enhanced tribological response of the nanocomposites, allowing their future use for GDI systems.

References:

[1] J. Gonzalez-Julian et al., Enhanced tribological performance of silicon nitride-based materials by adding carbon nanotubes. J. Am. Ceram. Soc. 94 (2011) 2542.

A6.4

61


Study of the abrasion resistance of new epoxy (ER) – ionic liquid (IL) materials with self-healing ability

Noelia Saurín*, José Sanes and María Dolores Bermúdez

Grupo de Ciencia de Materiales e Ingeniería Metalúrgica. Departamento de Ingeniería de Materiales y Fabricación. Universdad Politécnica de Cartagena

Campus de la Muralla del mar. 30202-Cartagena (Spain) * [email protected]

In the present work, new epoxy resin (ER) – ionic liquid (IL) dispersions [1] have been obtained and their abrasion resistance has been determined by multiple scratch test. The IL was added in a range of concentrations between 7 and 12 wt. %.

After the scratch tests, the viscoelastic recovery and healing ability of the damaged surface has been monitorized using optical and electronic microscopy and profilometry. The results are discussed on the basis of the curing procedure and are related to mechanical, thermal and dynamic-mechanical properties, and surface porosity of the new dispersions.

[1] N. Saurín, J. Sanes, M.D. Bermudez, Self-healing of abrasion damage in epoxy resin-ionic liquid nanocomposites. Tribol. Lett., 58 (2015) (4).

A6.5

62


Friday, 19th June SESSION B6

Surface Engineering. Chair: Prof. Dr. Jorge H. O. Seabra

63


Tribological properties of plunging-type textured surfaces produced by modulation-assisted machining

Patricia Iglesias (a)*, Christopher Saldana (b), Denny Sebastian (a), Rahul Gandhi (c)

a Rochester Institute of Technology, Rochester, NY, USA.

b Georgia Institute of Technology, Atlanta, GA, USA

c Pennsylvania State,PA, USA

* [email protected]

Surface texturing technology has started to gain attention in the tribology community as a method for improving friction and lubrication ability of various mechanical components [1]. Micro-sized depressions (e.g., grooves or dimples) on frictional surfaces act as fluid reservoirs and promote the retention of a lubricating thin film between mating components. Several fabrication techniques can be used to produce micro-dimple patterns on surfaces, but most of them show limitations when employed in practical efforts. The use of modulation-assisted machining (MAM) processes [2] provides a cost-effective approach for creating surface textures over large areas that offers high control over the characteristic geometry of the textured surface.

In this work, the effects of surface texturing and the influence of the dimensions of micro-sized depressions produced by MAM on wear performance are studied. Alloy 360 brass is mated with AISI 440C steel and studied using a ball-on-flat reciprocating configuration. Lubricated wear tests are carried out under conditions of variable frequency and normal load. The textured surfaces exhibited reduce wear under the highest frequency studied. The tribological performance of the surfaces is observed to depend on the size of the micro-dimples.

References:

[1] Etsion, I., and Sher, E., 2009, "Improving Fuel Efficiency with Laser Surface Textured Piston Rings," Tribology International, 42(4), pp. 542-547.

[2] Mann, J. B., Guo, Y., Saldana, C., Compton, W. D., and Chandrasekar, S., 2011, "Enhancing Material Removal Processes Using Modulation-Assisted Machining," Tribology International, 44(10), pp. 1225-1235.

B6.1

64

Tribological properties of TiC/a-C:H nanocomposite coatings prepared by HiPIMS

J.C. Sánchez-López (a)*, S. Dominguez-Meister (a), T.C. Rojas (a), M. Colasuonno (b), M. Bazzan (c), A. Patelli (b)

(a) Instituto de Ciencia de Materiales de Sevilla, Avda. Américo Vespucio 49, 41092 Sevilla, Spain

(b) Veneto Nanotech, via delle Industrie 5, 30175 Venezia, Italy

(c) Università di Padova, Dipartimento di Fisica, via Gradenigo 8, 35131 Padova, Italy

* [email protected]

High power impulse magnetron sputtering technology has been employed to prepare TiC/a-C:H nancomposite coatings from a titanium target in acetylene (C2H2) reactive atmospheres. Gas fluxes were varied from 3 to 10 sccm to obtain C/Ti ratios from 2 to 15 as measured by electron probe micronanalysis (EPMA). X-ray diffraction and transmission electron microscopy demonstrated the presence of TiC nanocrystals embedded in an amorphous carbon-based matrix. Hardness properties changed from around 17 to 10 GPa as the carbon content increases. Tribological properties were measured using a pin-on-disk tribometer in ambient air (RH= 30-40%) at 10 cm/s and 5N of applied against 6-mm 100Cr6 balls. The friction coefficient and the film wear rates were gradually improved from (0.3; 7×10-6 mm3/Nm) to (0.15; 2×10-7 mm3/Nm) by increasing the C2H2 flux. With the aim of understanding the tribological processes appearing at the contact region and the wear mechanism, microstructural and chemical investigations of the coatings were carried out before and after the friction test. EPMA, X-ray photoelectron and electron energy-loss spectroscopies were employed to obtain an estimation of the fraction of a-C:H phase, which can be correlated with the tribological behavior. Examination of the friction counterfaces (ball and track) by Raman microanalysis determined an increased ordering of the amorphous carbon phase when friction decreases. The tribological results will be compared with similar TiC/a-C(H) composites prepared by conventional direct current process.


B6.2

65


Wear and high temperature wear on MCrAl alloy on HVOF

Juan V. Miguel (a), Juan C. Pereira F. (a), Jenny C. Zambrano C. (b) and Vicente Amigó B. (a) *

a Instituto de Tecnología de Materiales ITM, Universidad Politécnica de Valencia, Spain.

b Centro de Investigación en Materiales CIM, Facultad de Ingeniería, Universidad de Carabobo, Venezuela.

* [email protected]

Wear and high temperature wear involve mechanical and chemical mechanisms and the combination of these, often result in significant wear and damage on metallic components. Thermal barrier coatings with MCrAl alloy can improve the tribological and friction wear behavior. One of the technique for applying Thermal barrier coatings is thermal spray and specially the High velocity Oxi-Fuel (HVOF) is one of the most employed techniques for materials as Nickel or Cobalt base alloys. In this investigation tribological behavior, on a dry friction and wear behavior at room temperature and high temperature of new developed NiCoCrAlY and CoNiCrAlY, has been perform in order to know the impact of the technique applied on the thermal barrier coating. Tribological wear tests were performed by sliding wear at room temperature, 350 and 500 ºC, with an Al2O3 ball on disk configuration tribometer. Wear test for NiCoCrAlY specimens has shown smaller weight losses and lower friction coefficient under high temperature, meanwhile has been increased for CoNiCrAlY coating. The main damage mode is abrasion, caused by oxides and partially-oxidized particles in the contact surface. The coatings and stainless steel substrate results were compared.

Keywords: friction; wear; CoCrAlY; HVOF; Thermal Spray; coating.

B6.3

66



Lubricious TiSi(V)N coatings for extreme temperature application

deposited by Deep Oscillation Magnetron Sputtering (DOMS) mode.

F. Fernandesa*, M.A. Mekichaa, J.C. Oliverira a, T. Polcar b, c, A. Cavaleiro a a - SEG-CEMUC - Department of Mechanical Engineering, University of Coimbra,

Rua Luís Reis Santos, 3030-788 Coimbra, Portugal.

b- National Centre for Advanced Tribology (nCATS), School of EngineeringSciences, University of Southampton, Highfield, Southampton, SO17 1BJ, UK.

c - Department of Control Engineering Czech Technical University in PragueTechnicka 2, Prague 6, 166 27 Czech Republic.

*e-mail: [email protected]

Development of new self-lubricant coating systems with control of thelubricous species diffusion have enormous potential to be used in the protection ofsurfaces in components for machining. Recently, the scientific community has beenfocused on the development of solid lubricant coatings by combining the intrinsicproperties of some binary or ternary films (CrN, TiN, CrAlN, TiAlN, YSZ, etc), that arevery hard and resistant to oxidation, with specific elements (metals) which diffused upto the surface and gave rise to low friction. The friction and wear resistance of thesefilms was shown to decrease; however, such improvements were of short durationdue to the rapid release of the metal, its quick depletion from the entire volume of thecoating and the consequent loss of the low-friction tribolayer after few minutes. Thecontrol of the metal out-diffusion is now one of the major challenges to achievesuitable long duration wear and friction properties without compromising the originalproperties of the host binary and ternary films. A possible solution is the use of acoating system with a dual phase structure, in which one of the phases could act as adiffusion barrier to the metal which should be responsible for the lubrication. This isthe case of the TiSiN, which if deposited as nanocomposite structure (TiN grainsimbibed in a Si-N matrix), the Si-N phase could work as an anti-diffusion barrier.Thus this work is devoted on the study of V additions (which is well known to formV2O5 with interesting tribological properties at high temperature) on the structureoxidation resistance and essentially on the tribological properties of TiSiN filmsdeposited by HiPIMS in Deep Oscillation Magnetron Sputtering (DOMS) mode. Thetribological properties of coatings were evaluated at room and high temperatures inreciprocating sliding equipment. After wear tests, the wear tracks and wear debriswere characterized by scanning electron microscopy with energy dispersive X-rayspectroscopy (SEM-EDS) and Raman spectroscopy. V additions to TiSiN decreasedthe wear rate and the friction coefficient of coatings, due to V2O5 oxide formation.

Keywords: Lubricious TiSi(V)N films, DOMS, Tribology

B6.4

67


Effect of spinels on the mechanical and tribological behavior of plasma sprayed alumina based coatings.

A. Rico*, C. J. Múnez, D. Verdi, M. Escobar, P. Poza, J. Rodriguez

DIMME. Grupo Durabilidad e Integridad Mecánica de Materiales Estructurales. Universidad Rey Juan Carlos. C/ Tulipán S/N, 28933 Móstoles (Madrid – Spain).

Corresponding author: [email protected]

Plasma sprayed ceramic coatings are widely used to protect metallic substrates when high temperature and/or friction are developed in service. In particular, alumina based coatings have been extensively used. Examples of applications are pistons in pumps or internal combustion engines and steam valve spindles. Alumina is hard, it shows a very high oxidation resistance and it is not permeable to aggressive gases. However, the alumina main drawback is its low fracture toughness. Brittle fracture is one of the most common wear mechanisms reported for ceramics. It is well known that the fracture toughness and the operative conditions are the key parameters controlling the crack propagation throughout the material. As a consequence, transition from mild to severe wear in ceramic coatings is mainly controlled by the fracture toughness of the coating. The typical solutions to improve the fracture behavior of alumina coatings are based on mixing alumina powders with other ceramic powders with superior toughness. Alumina – Titania, Alumina – Zircona and Alumina – Chromia systems are used in this way.

When a mixture of ceramics is thermally sprayed, a very complex microstructure is attained in the coating. Nevertheless, a common feature can be pointed out for different systems: formation of spinels from both oxides is commonly reported. These phases seem to play an important role in the fracture behavior of the coatings and subsequently in their tribological behavior.

This paper presents a summary of the work done in the microstructural, mechanical and tribological characterization of plasma sprayed alumina based coatings (Al2O3 – TiO2, Al2O3 – ZrO2 and Al2O3 – Cr2O3). Special attention is paid on the role played by spinels formed during deposition.

B6.5

68


Tribosystems based on self-mated multilayer micro/nanocrystalline HFCVD diamond coatings: effects of humidity and temperature

M. Shabani (a), C.S. Abreu (b)(c)*, F.J. Oliveira (a), J.R. Gomes (b)(d) and R.F. Silva (a)

(a) CICECO, Materials & Ceramic Eng. Dep., University of Aveiro, Portugal

(b) Microelectromechanical Systems Research Unit (MEMS), University of Minho, Portugal

(c) School of Engineering (ISEP), Polytechnic Institute of Porto, Portugal

(d) Mechanical Eng. Dep., University of Minho, Guimarães, Portugal

* [email protected]

Multilayer micro/nanocrystalline diamond coatings were grown onto silicon nitride (Si3N4) disc and ball substrates using a CH4/H2 gas mixture in a hot-filament CVD (HFCVD) reactor. Sliding wear tests of self-mated multilayer diamond coated large discs and balls were carried out in a ball-on-disc apparatus, using an unlubricated reciprocating sliding contact with a constant frequency of 1 Hz, during 1 h. Applied normal loads varied in the 40 N – 190 N range.In the present work, the relative humidity was changed from 10 % to 92 %, in addition with the temperature variation from ambient temperature to 250°C, separately. The effect of relative humidity and temperature on the phenomena of friction, wear and critical load of self-mated diamond coated Si3N4 tribosystems has been studied.As-grown and worn surfaces have been characterized using SEM, µ-Raman and AFM techniques in order to characterize the microstructure and quality of the produce films, as well as the predominant friction and wear mechanisms. Wear assessment was carried out by AFM data analysis due to the low wear damage observed.The sliding wear tests showed an initial high coefficient of friction shortly followed by very low steady-state friction values (~ 0.02-0.05). The wear performance of the films was characterised by very mild wear regimes, with wear rates k ~10-8 mm3 N-1m-1 and resulted from a self-polishing wear mechanism at the micro-scale of diamond asperities.In addition, the results of the unlubricated sliding tests indicate that the threshold load under tribological contact of self-mated multilayer diamond coatings increases by relative humidity increment and temperature curtailment.

B6.6

69



Posters

Instructions for poster presentations

The display for each poster on the panel of the poster board is 1 m wide x 1.2 m high. We would recommend you print your poster AO size in Portrait format: 841 mm x 1189 mm. Please note posters that are landscape or of any other size that exceeds the display area cannot be displayed on the boards.

It is recommended that you leave a margin of at least 75 mm around the poster.

When preparing your poster and considering how much of your display will be visible at eye-level, please bear in mind that panels will be mounted on stands.

Posters will be affixed with tape or double sided velcro. Please ensure that you bring some with you, however the Secretariat will have some available for delegate use at the conference.

A numbered panel will be allocated for each poster (this number will be communicated to you previously to the conference) and staff will be on hand at the conference to provide your poster panel number.

Posters should be set-up on Thursday 18th June in the corresponding panel before 9:30 am.

Poster session will take place during the coffee breaks of the first day of the conference (18th June) at 10:30-11:00 and 17:00-17:30. We strongly recommend to the authors to be close to their posters during the poster sessions to allow for discussion with the participants.

All posters should be retired from the panels before 15:00 of Friday 19th June.

70


Poster Session SESSION P1

Friction and Wear SESSION P2

Surface Engineering

71


THE MINIMUM QUANTITY OF LUBRICANT TECHNIQUE IN GRINDING OF STEEL USING A WHEEL CLEANING SYSTEM

Eduardo Carlos Bianchi (a)*, Hamilton Jose de Mello (a) and PauloRoberto de Aguiar (a)

a Univ. Estadual Paulista – UNESP- Campus de Bauru. Bauru School ofEngineering. Department of Mechanical Engineering/Department of Electrical

Engineering, Av. Luiz Edmundo C. Coube, 14-01, CEP 17033-360, Bauru, SP-Brasil.

* e-mail [email protected]

The application of minimum quantity of lubricant (MQL) for metal cutting hasemerged as an alternative for reducing the abundant flow of cutting fluids, thusachieving cleaner production [1]. Although considered an innovative technique ingrinding operations, the widespread application is hindered mainly due to the highheat generation and the clogging of wheel pores caused by machined chips, harmingthe final product quality and increasing tool wear [2]. This study sought to improveMQL use in grinding. Thus, besides the conventional MQL injected at thewheel/workpiece interface, a compressed air jet was also added, in order to clean theclogged wheel pores from the mixture of MQL oil and machined chips. Experimentswere conducted using external cylindrical plunge grinding on AISI 4340 quenchedand tempered steel, and a vitrified cubic boron nitrite (CBN) wheel. The lubri-refrigeration methods employed were the conventional with abundant flow,conventional MQL (both without any cleaning air jets) and MQL with the cleaning jet,directed at the surface at different angles of incidence. The main goal of theseexperiments was to verify the viability of replacing traditional abundance flow withMQL with wheel cleaning. The analyses were conducted by measuring the followingoutput variables of the process: workpiece surface roughness, roundness,diametrical wear of the wheel. Results show the possibility of implementing thecleaning jet technique as a technological improvement of the minimum quantity ofand grinding, in order to reduce the usage of cutting fluids. The MQL technique withcleaning compressed air jet, for a specific angle of incidence (30°) proved to beextremely efficient to obtain improved surface quality and accurate workpiece shape,as well as to reduce wear wheel and to prevent thermal damage, when compared tothe other lubri-refrigeration methods tested (without cleaning jet).

References:

[1] Dhar, N., Islam, S., Kamruzzaman, M., 2007. Effect of minimum quantitylubrication (MQL) on tool wear, and dimensional deviation in turning AISI-4340 steel.G.U. Journal of Science. 20, 23-32.

[2] Silva, L.R., Bianchi, E.C., Fusse, R.Y., Catai, R.E., Franc, T.V., Aguiar, P.R.,2007. Analysis of surface integrity for minimum quantity lubricant –MQL in grinding.International Journal of Machining Tools Manufacturing. 47, 412–418.

P1.1

72


Grinding of AISI 4340 steel when interrupted cutting by aluminum oxide grinding wheel

Hamilton José de Mello (a)*, Eduardo Carlos Bianchi (a) and PauloRoberto de Aguiar (a)

a Univ. Estadual Paulista – UNESP- Campus de Bauru. Bauru School ofEngineering. Department of Mechanical Engineering/Department of Electrical

Engineering, Av. Luiz Edmundo C. Coube, 14-01, CEP 17033-360, Bauru, SP-Brasil.

* e-mail [email protected]

There has been a great advance in the grinding process by developing dressing, lubri-refrigeration and other methods. Nevertheless, all those advances were gained onlyfor continuous cutting; in other words, the ground workpiece profile remainsunchanged. Hence, it becomes necessary to study grinding process in intermittentcutting (grooved workpiece – discontinuous cutting), as little or no knowledge andstudy have been developed for this purpose, since there is nothing found in formalliterature, except for grooved grinding wheels. During the grinding process, heatgenerated in the cutting zone is extremely high. Therefore, plenty of cutting fluids areessential to cool not only the workpiece but also the grinding wheel, improving thegrinding process. In this paper, grinding trials were performed using a conventionalaluminum oxide grinding wheel, testing samples made of AISI 4340 steel quenchedand tempered with 2, 6, and 12 grooves. The cylindrical plunge grinding was performedby rotating the workpiece on the grinding wheel. This plunge movement was made atthree different speeds. From the obtained results, it can be observed that roughnesstended to increase for testing sample with the same number of grooves, as rotationspeed increased. Roundness error also tended to increase as the speed rotationprocess got higher for testing sample with the same number of grooves. Grinding wheelwear enhanced as rotation speed and number of grooves increased. Power consumedby the grinding machine was inversely proportional to the number of grooves.Subsuperficial microhardness had no significant change. Micrographs reveal anoptimal machining operation as there was no significant damage on machined.

P1.2

73


Wear behaviour of ceramic composites for grinding wheels: Effect

of sintering temperature

P. Capela (a, b), S.F. Carvalho (a), R. Antunes (a), A. Guedes (a, b),M. Pereira (c), D. Soares (a, b) and J.R. Gomes (a, b)*

a Universidade do Minho, Departamento de Engenharia Mecânica, Guimarães,Portugal

b Microelectromechanical Systems Research Unit, MEMS, Guimarães, Portugal

c Centro de Física, Universidade do Minho, Braga, Portugal

* [email protected]

Grinding wheels are largely used in manufacturing industry to shape and finishmetals and other materials in an efficient way. The production of grinding wheelsusually consists on a sintering process involving ceramic powders, like alumina orsilicon carbide, and an agglomerating phase. During a grinding operation, more than90% of the particles of the dust come from the material being ground. However, theremaining part of loosed material is related to wear of the grinding tool anddetermines both the life of the abrasive part and the quality of surface finish. On theother hand, mechanical properties and wear resistance of bonded abrasive materialsthat constitute grinding wheels are directly related to processing parameters likecomposition and sintering temperature.

In this work, two compositions of vitreous bonded abrasive materials are consideredto compare the wear behaviour of a particular composition developed in the scope ofthis study with a reference material used in the industrial production of grindingwheels. Thus, bonded abrasive samples of a specific composition were processedusing three sintering temperatures (950, 1000 and 1050 ºC) as well as samplesreplicating an industrial composition and processing conditions. Wear tests wereperformed in a ball-on-disc geometry under unlubricated conditions. Alumina ballswere used as counterface material creating particularly hard contact conditions. Thenormal applied load varied in the range 5-20 N (at intervals of 5 N) and the slidingspeed and sliding distance were kept constant at 0.2 ms-1 and 185 m, respectively.

The wear rate of ceramic composites as well as of the corresponding aluminacounterface was measured by gravimetric method. The wear resistance of bondedabrasives developed in this study was compared with the reference industrial bondedabrasive and was correlated with the sintering temperature. Results showed that thegrinding performance of vitreous bonded abrasive materials can be optimized varyingthe sintering temperature. The dominant wear mechanisms as identified by SEManalysis were debonding of grit particles from the ceramic composite contact surfaceand fine scale abrasion of the protruding particles.

P1.3

74


ABRASIVE WEAR MECHANISMS OF GRAY CAST IRON APPLICATION TO CYLINDER BORE ABRASION

Luiz Alberto Franco (a)*, Amilton Sinatora (a) a)Surface Phenomena Laboratory, Polytechnic School, University of São Paulo, São

Paulo, Brazil Paulo *

[email protected]

Approximately 11% of the total energy supplied by the fuel is actually used to move an automobile internal combustion engine. Of those, 45% (5% of the total) are spent in the contact between cylinder and piston/rings [1]. Part of that energy is consumed by the abrasive action of particles that form in the interface between cylinder liner and piston, as a result of combustion and metal wear. Those particles are responsible for axial grooves that are observed in the liners of used engines [2]. The objective of this work was to get a better understanding of the wear mechanisms related to liner/bore grooving and to identify a laboratory testing setup that might reproduce them under controlled conditions. Specimens of Gray Cast Iron (GCI) - currently used in engine blocks and liners – and of AISI1070 steel with matrix hardness close to that found in GCI (≈200 HV30) were submitted to scratch tests in a tribometer. Half the samples had gone through a grinding operation resulting in a surface finishing with Sa≈0,20 and the other half were polished to Sa≈0,06. A conical, 60o apex angle, 5 µm tip radius indenter was used under normal loads varying from 20 mN to 200 mN. Besides the values of apparent friction coefficient (COF) directly provided by the tribometer, geometric parameters of the scratches – width, depth, average profile and material removal factor fab - were analyzed with an optical interferometry profilometer. SEM images allowed close examination of changes in abrasion mechanism with varying load and with the significantly different microstructures of GCI and steel. COF curves for both materials indicated consistent test conditions. It was found that scratches performed under 20 - 50 mN were similar to grooves observed in cylinder liners. COF values ranged from 0.20 – associated with micro-plowing – to 1.0 when micro-cutting prevailed. Initial estimates of energy consumption by abrasion are possible. Material removal factor (fab) [3] could not be associated with different abrasion mechanisms due to large dispersion in the area measurements leading to its calculation. Contrarily to what is indicated in the literature [4], no sharp transition between abrasion mechanisms was observed. Generally ground samples presented lower COF than polished ones. Further studies of the effect of surface finishing should be undertaken References: [1] Holmberg, K. et al, Global Energy Consumption due to Friction in Passenger Cars, Tribology International, 47, 2012. [2] Obara, R, Analysis of vertical abrasion grooves by means of fab (in Portuguese), Internal LFS Report, 2014. [3]Zum-Gahr, KH, Microstructure and wear of materials, Elsevier, 1987 [4] Hokkirigawa, K and Kato, K., An Experimental and Theoretical Investigation of Plowing, Cutting and Wedge Formation during Abrasion Wear, Tribology International, 21, 1988.

P1.4

75


Laser deposition of alumina and carbon black on AISI 4340 steel

G. Vasconcelos (a,b)*, Athanazi A. M. N. (b) Coreard C.C.G. (a,b), Oliveira, C.C.A. (a) Xavier S.R. (c)

a Institute for Advanced Studies – IEAv-DCTA – São José dos Campos – SP - Brazill

b Aeronautical Institute of Technology – ITA-DCTA

c Federal University of São Paulo - UNIFESP *

[email protected]

Abstract In the present work, a laser beam was used to cover, with graphite (solid lubricant material) mixed with alpha alumina (α-Al2O3), surfaces samples of AISI 4340 steel. The proportion of each component used was 50%, mixed in a planetary ball mill for 2 hours. A CO2 laser beam of 125 W and 0.2 mm beam diameter was used to irradiate the samples previously coated with the powders. The reduced friction of the mechanical part was confirmed by a tribo-tester in a reciprocal mode. Friction near to 0.15 were obtained with substrate steel hardened to 900 Hv with a top ceramics coatings of 1500Hv.

METHODOLOGY AND RESULTS Samples of AISI 4340 steel with a thickness of 3 mm and 20 mm diameter, previously sanded (SIC paper 600), were used. A CO2 laser with beam parameters of 125W and beam diameter of 0.2mm was used to irradiate the steel surface samples covered with a mixture of alumina, graphite plus carboxymethyl cellulose (as binder) mechanically mixed for 20 minutes in a plastic container with steel balls (52100) for the homogenization. Subsequently, the solution was sprayed with a pneumatic pistol on the surface of steel samples previously heated to 60°C. In the region of action beam on the sample surfaces, it was used a gas flow of nitrogen to prevent oxidation. To sintering the powders on the steel surface, the laser beam was focused on the steel surface. The irradiated samples were evaluated by pin-on-disc in the reciprocated mode with 5N applied on the 51200 steel ball of 3mm of diameter. The results of the test are presented in the Figure 1 and 2. A crater of 2micrometer depth and 0,15 of friction rate were obtained.

Fig. 1: Tracks topographies. Fig. 2: Profile crater after pin-on-disc test. References: 1-Y. Adraider et all; Laser induced deposition of alumina ceramic coating on stainless steel from dry thin films for surface modification, Ceramics International 40 (2014) 6151-6156.

P2.1

76


High temperature tribological characterization of TiAl laser cladding coating on Ti6Al4V alloy

Jenny C. Zambrano C. (a)*, Juan C. Pereira F. (b), Bernabé Carcel (c), and Vicente Amigó B. (a)



c Instituto Tecnológico de Óptica, Color e Imagen AIDO, Valencia, Spain.

* [email protected]

Ti6Al4V alloy has proven to be an important engineering material due to the excellent strength, weight ratio, high corrosion resistance and biocompatibility. However, the alloy is susceptible to mechanical degradation in applications involving sliding wear or abrasion. In order to improve wear resistance, coatings by laser cladding of intermetallic Ti48Al2Cr2Nb on Ti6Al4V have been developed. Different process parameters: laser power (W), scanning speed (mm/min), powder feeding rate (g/min) and preheating temperature of substrate (°C) were optimized, resulting in a microstructure of the coatings considered appropriate, with good metallurgical bond in all though cracks and pores are observed [1]. The composition and microstructure of the coatings was evaluated using optical microscopy (OM), scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis, further the tribological properties were evaluated using a ball on disk tribometer, with Al2O3 ball, constant speed of 0.1 m/s, 10 N load at room temperature and 500 °C. We evaluated the 3D surface topography obtained by the wear scar and calculated wear rate. The microstructure of the coatings consists of -TiAl phase and 2-Ti3Al. The wear test results at room temperature show a lower wear rate for the coating compared to the substrate. At high temperature the coating have a higher friction coefficient and a higher rate of wear is obtained when compared with the substrate, obtaining differences between the coatings depending on the wear mechanism observed in the worn surface.

Keywords: friction; wear; Ti6Al4V; Ti48Al2Cr2Nb; laser cladding.

References:

[1] Cárcel B., Serrano A., Zambrano J., Amigó V. Cárcel A., Laser Cladding of TiAl Intermetallic Alloy on Ti6Al4V - Process Optimization and Properties. Physics Procedia. 2014; 56: 284 – 293.

P2.2

77


Development of laser cladding MCrAlY coatings: high temperature friction and wear behavior

Juan C. Pereira F. (a)*, Jenny C. Zambrano C. (b), María J. Tobar (c), and Vicente Amigó B. (a)



c Departamento de Ingeniería Industrial II, Universidade da Coruña, Campus Ferrol, Spain.

* [email protected]

Temperature can have a significant effect on the extent of wear damage of metallic components. Thermal barrier coatings with MCrAlY alloy can improve the high temperature tribological and friction wear behavior. In this work the dry friction and wear behavior at room temperature and high temperature of new developed NiCoCrAlY and CoNiCrAlY laser cladding coatings were evaluated. Dense coatings, with good bonding to the AISI 304 substrate was obtained by coaxial laser cladding tracks (40% overlapping), with previously optimized laser parameters [1]. Tribological wear tests were performed by sliding wear at room temperature and 500 ºC, with an Al2O3 ball on disk configuration tribometer. The wear scar surface was evaluated by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) microanalysis. The 3D topography of the wear track was determined by inductive contact profilometer which enabled the wear rate calculation. The microstructure of the coatings consists of γNi/β-NiAl or γCo/β-(Co,Ni)Al phases depending on the chemical composition of the alloy, as confirmed by X-ray diffraction (XRD) analysis. The wear test results show a reduction in wear rate at high temperature for all materials tested. For the NiCoCrAlY coating, the high temperature also reduces the friction coefficient, while it significantly increases the friction coefficient of CoNiCrAlY coating. The main damage mode is abrasion and adhesion, caused by oxides and partially-oxidized particles in the contact surface. The coatings and stainless steel substrate results were compared, resulting in an improved wear behavior.

Keywords: friction; wear; MCrAlY; laser cladding; coating.

References:

[1] M. Tobar, J. Amado, A. Yáñez, J. Pereira, V. Amigó, Laser cladding of MCrAlY coatings on stainless Steel, Physics Procedia, 56 (2014) 276–283.

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Biotribological behavior of anti-bacterial Ag-C coatings prepared by DC-pulsed magnetron sputtering

S. Domínguez-Meister (a), T. C. Rojas (a) and J. C. Sánchez-López (a)

a Instituto de Ciencia de Materiales de Sevilla (CSIC-Univ. Sevilla), Avda. Américo Vespucio 49, 41092-Sevilla, Spain

* e-mail: [email protected]

Silver-containing carbon (Ag-C) is a promising material for biomedical implants due to its excellent combination of antibacterial and tribo-mechanical properties. In this work, a series of pure carbon samples was firstly deposited by DC-pulsed magnetron sputtering under different frequency and duty cycle conditions to determine the best experimental parameters in terms of tribological performance. Then, a set of Ag-C coatings with different Ag contents ranging from 2.5 to 18 at. % was deposited using the determined optimum conditions and a carbon target with silver nuggets on its surface. The study of Ag-C series by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) techniques revealed a columnar structure with Ag nanoparticles embedded. A heterogeneous Ag particle size distribution between 1.5 and 100 nm was found. The Ag particles were mainly located in the columnar boundaries and sometimes segregated to the surface. Raman analysis of the D and G peaks showed a similar disordered carbon structure, with no significant variation when Ag is introduced. The study of the tribological properties in air conditions showed a small decrease in the friction coefficient (0.22→0.17) and slight increase in the wear rate (1.6·10-7→3·10-7mm3/Nm) when the Ag is present regardless its concentration. With the aim of simulating the human body environmental conditions, tribological tests were carried out using fetal bovinum serum as surrounding medium and a constant temperature of 37ºC. The results showed a small decrease of the wear rate (~1·10-7 mm3/Nm) indicating that the behaviour is optimum in the biological environment. To investigate the mechanical properties, nanoindentation studies were made over three representative samples: carbon reference, low and high amount of silver. The results showed a decrease of the hardness when the silver is introduced (17→13 GPa) that can explain the observed slight decrease of film wear resistance.

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List of participants

Author Paper Session Page

AAbreu, Cristiano S. Sur_06_Abreu B6 B6.6 69

Álvarez, D. Cas_06_Panera A3 A3.4 39

Amigó B., Vicente Sur_03_Amigo Sur_P02_Zambrano Sur_P03_Pereira

B6 P2 P2

B6.3 P2.2 P2.3

66 77 78

Antunes, Pedro V. Fri_05_Antunes Bio_04_Vilhena

B2 B3

B2.3 B3.3

30 44

Antunes, R. Fri_P03_Gomes P1 P1.3 74

Arana, José Luís Tri_02_Lopez B4 B4.4 56

Arancón, J. Cas_06_Panera Ctt_03_García

A3 A4

A3.4 A4.4

39 51

Artímez, J. M. Cas_06_Panera A3 A3.4 39

Athanazi, A. M. N. Sur_P01_Vaconcelos P2 P2.1 76

BBayón, Raquel Tri_02_Lopez B4 B4.4 56

Bazzan, M. Sur_02_Sanchez B6 B6.2 65

Behyan, Shirin Lub_02_Hobbs A2 A2.2 22

Belmonte, Manuel Fri_01_Llorente Micro_03_Belmonte

B2 A6

B2.1 A6.4

28 61

Belzunce, J. Cas_06_Panera Ctt_03_García

A3 A4

A3.4 A4.4

39 51

Bentes, A.C. Bio_02_Gomes B3 B3.1 42

Bermúdez Olivares, María Dolores Fri_08_Espinosa Micro_04_Saurin

B2 A6

B2.6 A6.5

34 62

Berriozabal, E. Tri_03_Igartua A6 A6.2 59

Bianchi, Eduardo Carlos Fri_P01_Bianchi Fri_P02_de_Mello

P1 P1

P1.1 P1.2

72 73

Brinksmeier, E. Bio_03_Seidel B3 B3.2 43

CCambra, J.F. Tri_03_Igartua A6 A6.2 59

Campos, Armando V. Cas_03_Goncalves A3 A3.2 37

Capela, P. Fri_P03_Gomes P1 P1.3 74

Carcel, B. Sur_P02_Zambrano P2 P2.2 77

Carneiro, Carla Bio_05_Carneiro B3 B3.4 45

80


Author Paper Session PageCarrascal, D. Cas_06_Panera A3 A3.4 39

Carvalho Greco, Luigi Mod_03_Greco A4 A4.2 49

Carvalho, S.F. Fri_P03_Gomes P1 P1.3 74

Castell, P. Fri_06_Pascual B2 B2.4 31

Castillo, A. Fri_04_Coello B2 B2.2 29

Castro, Jorge Cas_04_Castro A3 A3.3 38

Catalá Carrión, R. Bio_08_Igual B4 B4.3 55

Cavaleiro, A. Sur_04_Fernandes B6 B6.4 67

Coello , Juana Fri_04_Coello B2 B2.2 29

Colasuonno, M. Sur_02_Sanchez B6 B6.2 65

Coreard, C.C.G. Sur_P01_Vaconcelos P2 P2.1 76

Dde Aguiar, Paulo Roberto Fri_P01_Bianchi

Fri_P02_de_Mello P1 P1

P1.1 P1.2

72 73

de Mello, Hamilton José Fri_P01_Bianchi Fri_P02_de_Mello

P1 P1

P1.1 P1.2

72 73

Díaz, Cristina Bio_07_Diaz B4 B4.2 54

Doerr, N. Tri_03_Igartua A6 A6.2 59

Dominguez-Meister, S. Sur_02_Sanchez Sur_P04_Sanchez

B6 P2

B6.2 P2.4

65 79

Dufresne Jr., Peter Lub_02_Hobbs A2 A2.2 22

EEscobar, M. Sur_05_Rico B6 B6.5 68

Espinosa Rodríguez, Tulia Fri_08_Espinosa B2 B2.6 34

Esteves, Miguel Mod_02_Esteves A4 A4.1 48

Evans, John Lub_02_Hobbs A2 A2.2 22

FFernandes, Carlos M.C.G. Lub_05_Seabra

Cas_02_Fernandes A2 A3

A2.5 A3.1

25 36

Fernandes, Filipe Sur_04_Fernandes B6 B6.4 67

Fernández Gonzalez, A. Cas_02_Fernandes A2 A2.6 26

Fernández Ruiz-Morón, Luis Keynote Lecture A1 Plenary 12

Fidalgo, E. Ctt_03_García A4 A4.4 51

Figueiredo-Pina, Célio Bio_05_Carneiro Bio_06_Figueiredo

B3 B4

B3.4 B4.1

45 53

Franco, Luiz Alberto Fri_P04_Franco P1 P1.4 75

Fuentes, Gonzalo Bio_07_Diaz B4 B4.2 54

81



GGabler, C. Tri_03_Igartua A6 A6.2 59

Gandhi, Rahul Sur_01_Iglesias B6 B6.1 64

García, Alberto Lub_05_Seabra Lub_06_García

A2 A2

A2.5 A2.6

25 26

García, Pablo Cas_06_Panera Ctt_03_García

A3 A4

A3.4 A4.4

39 51

Garrido, M. A. Ctt_02_Garrido Micro_02_Verdi

A4 A6

A4.3 A6.3

50 60

Gomes, Jose R. Bio_02_Gomes Sur_06_Abreu Fri_P03_Gomes

B3 B6 P1

B3.1 B6.6 P1.3

42 69 74

Gonçalves, David Cas_03_Goncalves A3 A3.2 37

González, Rubén Lub_05_Seabra Lub_06_García

A2 A2

A2.5 A2.6

25 26

González-Julián, Jesús Micro_03_Belmonte A6 A6.4 61

Graça, Beatriz Cas_03_Goncalves A3 A3.2 37

Guedes, A. Fri_P03_Gomes P1 P1.3 74

Guedes, Mafalda Bio_06_Figueiredo B4 B4.1 53

HHammami, Maroua Cas_02_Fernandes A3 A3.1 36

Hernandez Battez, Antolin Lub_05_Seabra Lub_06_García

A2 A2

A2.5 A2.6

25 26

Hobbs, Matthew G. Lub_02_Hobbs A2 A2.2 22

Huesmann-Cordes, A. G. Bio_03_Seidel B3 B3.2 43

IIgartua, Amaya Tri_02_Lopez

Tri_03_Igartua B4 A6

B4.4 A6.2

56 59

Iglesias, Patricia Lub_03_Iglesias Sur_01_Iglesias

A2 B6

A2.3 B6.1

23 64

Igual Muñoz, Anna Bio_08_Igual B4 B4.3 55

KKennepohl, Pierre Lub_02_Hobbs A2 A2.2 22

82



LLi, Hu Tri_01_Wang A6 A6.1 58

Lima Stoeterau, R. Mod_03_Greco A4 A4.2 49

Llorente, Javier Fri_01_Llorente B2 B2.1 28

López, Ainara Tri_02_Lopez B4 B4.4 56

MMacián, Vicente Lub_01_Miro A2 A2.1 21

Martínez, A. Fri_04_Coello B2 B2.2 29

Martins de Souza, R. Mod_03_Greco A4 A4.2 49

Martins, Ramiro C. Lub_05_Seabra Cas_02_Fernandes

A2 A3

A2.5 A3.1

25 36

Masuda, Gen Lub_04_Minami A2 A2.4 24

Mazuco, F. Cas_05_Zuleta A3 A3.5 40

McNabb, Kelly B. Lub_03_Iglesias A2 A2.3 23

Medina, N. Fri_04_Coello B2 B2.2 29

Mekicha, M.A. Sur_04_Fernandes B6 B6.4 67

Miguel Guillén, Juan Vicente Sur_03_Amigo B6 B6.3 66

Miguel, V. Fri_04_Coello B2 B2.2 29

Minami, Ichiro Lub_04_Minami Tri_03_Igartua

A2 A6

A2.4 A6.2

24 59

Miranzo, Pilar Fri_01_Llorente B2 B2.1 28

Miró Mezquita, Guillermo Lub_01_Miro A2 A2.1 21

Monge, Raquel Lub_05_Seabra Lub_06_García

A2 A2

A2.5 A2.6

25 26

Morales-Hurtado, Marina Bio_01_Morales B3 B3.5 46

Morina, Ardian Tri_01_Wang A6 A6.1 58

Múnez, C. Micro_02_Verdi Sur_05_Rico

A6 B6

A6.3 B6.5

60 68

NNavarro Laboulais, J. Bio_08_Igual B4 B4.3 55

OOliveira, F.J. Sur_06_Abreu B6 B6.6 69

Oliveira, C.C.A. Sur_P01_Vaconcelos P2 P2.1 76

Oliverira, J.C. Sur_04_Fernandes B6 B6.4 67

83



PPagano, Francesco Tri_02_Lopez

Tri_03_Igartua B4 A6

B4.4 A6.2

56 59

Panera, María Cas_06_Panera Ctt_03_García

A3 A4

A3.4 A4.4

39 51

Pascual, F.J. Fri_06_Pascual B2 B2.4 31

Patelli, A. Sur_02_Sanchez B6 B6.2 65

Peppelman, M. Bio_01_Morales B3 B3.5 46

Pereira F., Juan Carlos Sur_03_Amigo Sur_P02_Zambrano Sur_P03_Pereira

B6 P2 P2

B6.3 P2.2 P2.3

66 77 78

Pereira, M. Fri_P03_Gomes P1 P1.3 74

Pérez, H. Cas_06_Panera A3 A3.4 39

Pérez, Tomás Lub_01_Miro A2 A2.1 21

Pinho, Samuel Cas_03_Goncalves A3 A3.2 37

Polcar, T. Sur_04_Fernandes B6 B6.4 67

Poza, P. Micro_02_Verdi Sur_05_Rico

A6 B6

A6.3 B6.5

60 68

Prieto, German Fri_07_Prieto B2 B2.5 33

Puértolas, José Antonio Fri_06_Pascual B2 B2.4 31

QQuiles, L. Fri_06_Pascual B2 B2.4 31

RRabenstein, A. Bio_03_Seidel B3 B3.2 43

Ramalho, A. Fri_05_Antunes Bio_04_Vilhena Mod_02_Esteves

B2 B3 A4

B2.3 B3.3 A4.1

30 44 48

Reis, K. Bio_02_Gomes B3 B3.1 42

Respatiningsih, Catur Y. Lub_04_Minami A2 A2.4 24

Rico, Álvaro Sur_05_Rico B6 B6.5 68

Rodrigues, Micaela Bio_06_Figueiredo B4 B4.1 53

Rodríguez, Jesús Ctt_02_Garrido Sur_05_Rico

A4 B6

A4.3 B6.5

50 68

Rojas, T.C. Sur_02_Sanchez Sur_P04_Sanchez

B6 P2

B6.2 P2.4

65 79

Román, Benito Fri_01_Llorente B2 B2.1 28

Ruiz, Santiago Lub_01_Miro A2 A2.1 21

84



SSalazar, A. Sur_05_Rico B6 B6.5 68

Saldana, Christopher Sur_01_Iglesias B6 B6.1 64

Sánchez-López, Juan Carlos Sur_02_Sanchez Sur_P04_Sanchez

B6 P2

B6.2 P2.4

65 79

Sanes Molina, José Fri_08_Espinosa Micro_04_Saurin

B2 A6

B2.6 A6.5

34 62

Saurín, Noelia Micro_04_Saurin A6 A6.5 62

Schneider, Johannes Micro_03_Belmonte A6 A6.4 61

Seabra, Jorge H.O. Lub_05_Seabra Cas_02_Fernandes Cas_03_Golcalvez Cas_04_Castro

A2 A3 A3 A3

A2.5 A3.1 A3.2 A3.3

25 36 37 38

Sebastian, J. Denny Sur_01_Iglesias B6 B6.1 64

Seidel, Benedikt Bio_03_Seidel B3 B3.2 43

Shabani, M. Sur_06_Abreu B6 B6.6 69

Silva, R.F. Sur_06_Abreu B6 B6.6 69

Sinatora, Amilton Cas_05_Zuleta Fri_P04_Franco

A3 P1

A3.5 P1.4

40 75

Soares, D. Fri_P03_Gomes P1 P1.3 74

Sousa, Joana Bio_05_Carneiro B3 B3.4 45

Souza, J.C.M. Bio_02_Gomes B3 B3.1 42

Spencer, Nicholas Keynote Lecture A5 Plenary 13

TTanaka, D.K. Cas_05_Zuleta A3 A3.5 40

Tobar Vidal, M.J. Sur_P03_Pereira P2 P2.3 78

Tormos, Bernardo Lub_01_Miro A2 A2.1 21

Tuckart, W. R. Fri_07_Prieto B2 B2.5 33

VVan der Heide, E. Bio_01_Morales B3 B3.5 46

Van Erp, P. Bio_01_Morales B3 B3.5 46

Vasconcelos, Getulio Sur_P01_Vaconcelos P2 P2.1 76

Verdi, Davide Micro_02_Verdi Sur_05_Rico

A6 B6

A6.3 B6.5

60 68

Viesca, José L. Lub_05_Seabra Lub_06_Garcia

A2 A2

A2.5 A2.6

25 26

Vilhena, Luis M. Fri_05_Antunes Bio_04_Vilhena

B2 B3

B2.3 B3.3

30 44

85



WWang, Chun Tri_01_Wang A6 A6.1 58

XXavier, S.R. Sur_P01_Vaconcelos P2 P2.1 76

ZZambrano C., Jenny C. Sur_03_Amigo

Sur_P02_Zambrano Sur_P03_Pereira

B6 P2 P2

B6.3 P2.2 P2.3

66 77 78

Zeng, X. Bio_01_Morales B3 B3.5 46

Zuleta Durango, A. Cas_05_Zuleta A3 A3.5 40

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Documents

VIII IBERIAN CONFERENCE ON TRIBOLOGY