1 Physical-Technical Institute of National Academy of Sciences Belarus, Minsk Founded - 1931...

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Physical-Technical Institute of Physical-Technical Institute of National Academy of SciencesNational Academy of Sciences

Belarus, MinskBelarus, Minsk

Founded - 1931Personnel- 370 Laboratories- 30

Activity linesActivity lines::

Е-mail: phti@tut.byTel/fax: (+375-17-263-76-93)

2. 2. NewNew technologies for thermal andtechnologies for thermal and deformation deformation processing of materialsprocessing of materials

1. 1. New materials for New materials for machine buildingmachine building

http://www.phti.belhost.by

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Physical-Technical Institute ofPhysical-Technical Institute of National Academy of SciencesNational Academy of Sciences, ,

Belarus, MinskBelarus, Minsk

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««Deformed ironsDeformed irons make up a new make up a new class of materialsclass of materials»»

A. I. PokrovskyA. I. Pokrovsky

Physical-Technical Institute ofPhysical-Technical Institute of National Academy of SciencesNational Academy of Sciences, ,

Belarus, MinskBelarus, Minsk

((Example of unusual action onExample of unusual action on traditionaltraditional materialmaterial))

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Iron,Iron, classical approach:classical approach:Excellent casting materialHardly deformableMaterial only for non-critical items

New view onNew view on ironiron::1. Deformed iron enters the class of

materials of high quality

2. Has superior properties

3. Its area of applications is wider

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1. Higher thermal conductivity results in rapid heat sink (cylinder sleeves, guide valve sleeves)

2. Antifriction properties (camshafts, crank shafts, piston rings)

3. Quicker damping of vibrations and sounds (valve pushers)

4. Lighter by 10% (casings, pallets)

Iron benefits as compared to steel

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Drawbacks of iron:

Low mechanical properties

Casting defects degrading the properties

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Traditional means of increasing Traditional means of increasing mechanicalmechanical properties of iron:properties of iron: Alloying Modifying Thermal treatment

Quality of a casting,Casting defects:

Problems do not vanish

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Advantages of deformation Advantages of deformation processingprocessing : :

3. Accuracy of shaping

2.Increase of strengthcharacteristics

1.Guaranteed quality of metal

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Why we turn to deformation of iron Why we turn to deformation of iron ::

Physical-TechnicalPhysical-Technical Institute of NationalInstitute of National Academy Academy of Sciences, Belarusof Sciences, Belarus, , MinskMinsk

• Casting defects such as pores and cavities are avoided

• Mechanical properties are enhanced up to the level of alloyed steel

(strength is 1200 MPa, elongation 15%)

• Antifriction characteristics are increased by a factor of 1.5

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Control of graphite shapeControl of graphite shape Traditional Traditional approachapproach::

Change of graphite shape from branchy to compact and spherical ones

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Control of graphite Control of graphite shape on deformingshape on deforming

And vice versa, from sphericalshape to fibers

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WeWe tested thetested the following classes of irons following classes of irons ::

Gray ironGray iron Mottled ironMottled iron

Malleable ironMalleable iron High-strength ironHigh-strength iron

And have foundAnd have found the most the most ADVANTAGEOUS ONESADVANTAGEOUS ONES

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There are There are 5 5 groups of groups of ««knowknow--howhow»» : :

1. Alloying diagrams

2. Preliminary thermal treatment for improvement of deformability

3. Design of press-forging tool

4. Temperature-force parameters of deforming

5. Finishing thermal treatment

Conditions of iron deformingConditions of iron deforming

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Example of deliberate selectionExample of deliberate selectionof parameters for iron deformingof parameters for iron deforming

Press forging from a solid billet FOR ONE STROKE

Part: body of drill chuck

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Example ofExample of violating the ironviolating the iron deforming conditionsdeforming conditions

Finishedpart

High-quality semi-finished product

Spoiled product

(press-forgingtemperature is

violated)

Part: Cylinder of jack plunger for MAZ truck

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SchematicSchematic diagram diagram ofof iron deforming iron deforming

1 – Iron billet heated to high temperature

2 – Body of press tool

3 – Intermediate medium

4 - Punch

5 – Die

6 - Guide bush

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Making the samples forMaking the samples for investigationsinvestigations

Transverse samples:

Longitudinal samples:Incomingcasting billet

Press-forgedrod

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Wearing weight loss during dry friction, deformed Wearing weight loss during dry friction, deformed conditioncondition: :

(D(Decrease by a factor of 1.5 as compared that in casting condition)ecrease by a factor of 1.5 as compared that in casting condition)

0

5

10

15

20

25

Wea

rin

g w

eig

ht

loss

aft

er 1

6 th

ou

s. c

ycle

s, k

g/m

3 1

0-5

HSI

GI

MI

MtI

80%-deformation

Casting

In order of decreasing wear resistance:

1. Mottled iron, (MtI)2. High-strength iron,

(HSI)3. Malleable iron, (MI)4. Gray iron, (GI)

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Significant feature of deformation isSignificant feature of deformation is anisotropy ofanisotropy of structure and propertiesstructure and properties

Longit

udinal

secti

on Cross

secti

on

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Anisotropy ofAnisotropy of wear duringwear during dry frictiondry friction

6

8

10

12

14

16

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0 20 40 60 80Degree of deformation, %

We

ari

ng w

eig

ht

loss, k

g/m

3 10-5

Longitud. sample

Transverse samp.

Longitud. sample

Transverse samp.

Ferrite

structure

Pearlite

structure

Longitudinal

sample

Transverse sample

The selection is made of optimum relationships

between:

Deformation parameters

Microstructures

Friction directions

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DryDry FrictionFriction: : Coefficient ofCoefficient of friction can be decreased friction can be decreased

by a factor of 2.5by a factor of 2.5

Longitudinal

sample

Transverse

sample

0,1

0,2

0,3

0,4

0,5

0 20 40 60 80

Degree of deformation, %

Coe

ffic

ien

t o

f fri

ction

Transverse samples

Longitudinal samples

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Probable factors that cause improvement of deformed iron

characteristics:

1. Refinement of austenite grain 2. Change in pearlite morphology3. Change in graphite morphology 4. Origination of new graphite inclusions

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1. 1. Refinement of austenite grainRefinement of austenite grain

Grain number 3-4

Grain number 8-9

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2. 2. Changes in pearlite morphologyChanges in pearlite morphology

х 15000

х 10000

х 10000

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3. 3. Changes in graphite morphologyChanges in graphite morphology

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4. 4. Formation ofFormation ofnewnew graphitegraphite

inclusionsinclusions

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Industrial testing ofIndustrial testing ofdeformed irondeformed iron

PhysicalPhysical--TechnicalTechnical Institute of NationalInstitute of National Academy of Sciences, Belarus,Academy of Sciences, Belarus, MinskMinsk

Various parts have been offered but the greatest interest has been shown in

2 lines(that will be discussed below):

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High-quality billets ofHigh-quality billets of pistonpistonandand sealing ringssealing rings made frommade from deformed irondeformed iron

PhysicalPhysical--TechnicalTechnical Institute of NationalInstitute of National Academy Academy of Sciences, Belarus,of Sciences, Belarus, MinskMinsk

Their mechanical properties

are 2 times higher than those of cast rings

Any failures are absent 7-fold decrease of lubricant

bleeding No wear increase of mating part Stable and one and the same

quality throughout the whole height

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Appreciation in Belarus and RussiaAppreciation in Belarus and Russia

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High-quality billets ofHigh-quality billets of gears gears made frommade from deformed irondeformed iron

PhysicalPhysical--TechnicalTechnical Institute of NationalInstitute of National Academy Academy of Sciences, Belarus,of Sciences, Belarus, MinskMinsk

Strength is at the level of alloyed steel

Noise in trucks is lower by 3 to 4 db

Weight of gears is lower by 9 % (the economy for one set is 700 g)

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Disadvantages of technology

High power requirements. A billet is to be heated.

Some time is required for designing, fabricating and adjustment of press-forging tool.

Costly press tool.

Economically sound are:

Both mass production from 50 thousand pc per year (e. g., gears for MAZ) and piece production

(e. g., piston rings «Formula-1»).

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Present-day investigationproblems:

1. Technological directional thrust is ahead of fundamental knowledge.

2. The factors that cause iron hardening are still not completely cleared up.

3. The role played by structure factorsin hardening is ambiguous.

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We are in search of potential We are in search of potential partners forpartners for::

Performing joint scientific investigations

Cooperation in delivering billets made from deformed iron.

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From the scientific viewpoint From the scientific viewpoint wewe are interested inare interested in::

Physical factors and mechanisms responsible for iron hardening during hot deformation

Computer simulation of iron hardening processes; Tribotechnical tests Investigation of iron physical characteristics Construction of mathematical models of structure

formation Investigation of fine structure (dislocations and

point defects).

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From the practical viewpoint From the practical viewpoint we are interested inwe are interested in::

Widening the area of deformed iron use as an effective competitive alternative to steel roll stock for manufacturing automotive and machine-building parts

Joint realization of our technological developments during production of items from deformed iron with improved characteristics

We are now prepared to produce rods for investigations as well as gear and sealing ring billets of various typical sizes

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ContactsContacts:: Physical-Technical Institute of National Academy

of Sciences of Belarus

10 Kuprevich St., Minsk, 220141, Belarus

Artur I. Pokrovsky, Cand. Tech. Sci.,

Leading Scientific Worker

Tel.: +10375-29-663-58-38

Е-mail: arturu@tut.by

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Thank youThank youfor attentionfor attention!!