UNCLASSIFIED

UNCLASSIFIED

EXPERIMENTAL METHODS FOR

MULTI-GENRE NETWORKS

Tribology Behavior of Novel PEEK-MAX

or PEEK-MAB Composites during Fuel

Lubricated Sliding

Caleb Matzke

Mechanical Engineering

University of North Dakota

ARL Mentor: Dr. Stephen Berkebile

Directorate / Division: VTD / VICTOR ERP

Project Duration: 06/01/2020 to 08/21/2020

Motivation• High pressure fuel pumps are a vital component in Unmanned

Aerial Systems

• Wear and scuffing are major issues due to low lubricity fuel in

fuel pumps, fuel injectors and valves [1]

• Lubricity = Chemistry + Viscosity + Solid Lubricants

• Chemistry varies between fuels which results in different

material interactions (polar, non-polar, etc.)

• Viscosity directly affects friction and fluid film thickness

Objective• Overall: Expand operational capabilities to increase lifetime and

robustness of diesel fuel systems run with lower viscosity fuel

• Objective: Determine wear and coefficient of friction of MAX or

MAB phase composites with PEEK which are lubricated with

fuels of different chemistries (alkane, alcohol, hydrocarbon mix)

• Hypothesis: Addition of MAX/MAB-phase additions to PEEK will

decrease wear vs. PEEK during wet sliding (Dr. Gupta’s group

has validated this concept in dry sliding)

Plunger TappetCamshaft

assembly

High Pressure

Fuel Pump

Experimental Method• CSM Instruments Tribometer– Linear velocity: 31.4 cm/s

– Sliding distance of 500 m

– Load of 5, 10, and 20 N

– Disk radius of 10 mm

– 6 mm diameter alumina ball

• Syringe Pump– Lubricant flow rate of 0.5 mL/min• Ethanol, F-24 fuel, Dodecane

• Wear– Measure weight before and after with precision scale

Pin on Disk method

BackgroundMAX/MAB phases• Ternary solids

• Used to enhance tribological properties

• Desirable properties– Highly Damage resistant

– Creep resistant

– Readily machinable

– Conductive

– High oxidation resistance

• MAX/MAB phases of interest– Cr2AlC (MAX phase)

– MoAlB (MAB phase)

– These show promising wear results during dry sliding

• The MAX/MAB phases are being used as reinforcements in

composites

PEEK/MAX-PHASE OR PEEK/MAB-PHASE COMPOSITES• Polyether Ether Ketone (PEEK) – semicrystalline thermoplastic

polymer

• MAX/MAB phase reinforcements in PEEK have been shown to

act as a solid lubricants during dry sliding

• No liquid lubrication studies yet

[2] SEM SE image of the polished surface of: (a) PEEK–5%312Si

PEEK (inset shows the SEM SE polished surface of PEEK) surface,

(b) BSE image of the same region, (c) PEEK–10%312Si PEEK, (d)

BSE image of the same region, (e) PEEK–20%312Si PEEK, (f) BSE

image of the same region, (g) PEEK–30%312Si PEEK, and (h) BSE

image of the same region.

Fig A

Fig B Fig C

Fig A: Magnuson, M., & Mattesini, M. (2017). Chemical bonding and electronic-structure in MAX phases as viewed by X-ray spectroscopy and density functional theory.

Fig B: Kota, S., Zapata-Solvas, E., Ly, A. et al. Synthesis and Characterization of an Alumina Forming Nanolaminated Boride: MoAlB.

Fig C: Zhu, J. et al Recent advance in MXenes: A promising 2D material for catalysis, sensor and chemical adsorption

Discussion and Conclusions• Experiments with increased time duration should be conducted

to study the affect of MAX or MAB phase reinforcements under

F-24 lubrication

• Larger wear seen in the samples lubricated by F-24 compared to

those lubricated with ethanol– May be due to the chemical interactions of the fuel with the PEEK but more

experiments and analysis must be done to confirm

• Reliability should be increased with more replicate experiments

• PEEK-10% MoAlB is promising under ethanol lubrication as it

displays lower wear at 5 N and 20 N loads compared to Pure

PEEK

AcknowledgementsOther contributorsNikhil Murthy, Nickolas Johnson, Ryan Riihinen, Maharshi Dey, Sabah Javaid

Funding SourcesU.S. Army CRADA, Dean Professorship awarded to Dr. Gupta,

Army Educational Outreach Program College Qualified Leaders

Path Forward• Increase sample size

• Increased experiment duration for F-24 lubricated experiments

• Additional fuels– Dodecane

• Additional compositions– Ultra high molecular weight polyethylene (UHMWPE) - MAX/MAB

– 52100 steel – MAX/MAB

Results

0

0.025

0.05

0.075

0.1

0.125

0.15

0 100 200 300 400 500

Co

effi

cien

t o

f Fr

icti

on

(µ

)

Sliding Distance (m)

Pure PEEK

0

0.025

0.05

0.075

0.1

0.125

0.15

0 100 200 300 400 500

Co

effi

cien

t o

f Fr

icti

on

(µ

)

Sliding Distance (m)

PEEK-10% Cr2AlC(3 runs)

0

0.025

0.05

0.075

0.1

0.125

0.15

0 100 200 300 400 500

Co

effi

cien

t o

f Fr

icti

on

(µ

)

Sliding Distance (m)

PEEK-10% MoAlB(3 runs)

averaged µ

Pure PEEK 0.063

PEEK-10% Cr2AlC 0.060

PEEK-10% MoAlB 0.040

0

0.025

0.05

0.075

0.1

0.125

0.15

Co

effi

cien

t o

f Fr

icti

on

(µ

)

Average of All Runs

(3 runs)

Ethanol, Load: 5 N

0

0.02

0.04

0.06

0.08

0.1

0 100 200 300 400 500

Co

effi

cien

t o

f Fr

icti

on

(µ

)

Sliding Distance (m)

Pure PEEK

0

0.02

0.04

0.06

0.08

0.1

0 100 200 300 400 500

Co

effi

cien

t o

f Fr

icti

on

(µ

)

Sliding Distance (m)

PEEK-10% Cr2AlC(3 runs)

0

0.02

0.04

0.06

0.08

0.1

0 100 200 300 400 500

Co

effi

cien

t o

f Fr

icti

on

(µ

)

Sliding Distance (m)

PEEK-10% MoAlB

averaged µ

Pure PEEK 0.056

PEEK-10% Cr2AlC 0.043

PEEK-10% MoAlB 0.072

0

0.02

0.04

0.06

0.08

0.1

Co

effi

cien

t o

f Fr

icti

on

(µ

) Average of All Runs

(3 runs)

(3 runs)

Ethanol, Load: 10 N

0

0.02

0.04

0.06

0.08

0.1

0 100 200 300 400 500

Co

effi

cien

t o

f Fr

icti

on

(µ

)

Sliding Distance (m)

Pure PEEK

0

0.02

0.04

0.06

0.08

0.1

0 100 200 300 400 500

Co

effi

cien

t o

f Fr

icti

on

(µ

)

Sliding Distance (m)

PEEK-10% Cr2AlC

0

0.02

0.04

0.06

0.08

0.1

0 100 200 300 400 500

Co

effi

cien

t o

f Fr

icti

on

(µ

)

Sliding Distance (m)

PEEK-10% MoAlB

averaged µ

Pure PEEK 0.042

PEEK-10% Cr2AlC 0.053

PEEK-10% MoAlB 0.046

0.00

0.02

0.04

0.06

0.08

0.10

Co

effi

cien

t o

f Fr

icti

on

(µ

) Average of All Runs

(3 runs) (3 runs)

(3 runs)

Ethanol, Load: 20 N

0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0.16

0.18

0.2

0 100 200 300 400 500

Co

effi

cein

t o

f Fr

icti

on

(µ

)

Sliding Distance (m)

Pure PEEK

0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0.16

0.18

0.2

0 100 200 300 400 500

Co

effi

cen

t o

f Fr

icti

on

(µ

)

Sliding Distance (m)

PEEK-10% Cr2AlC

(5 runs)

0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0.16

0.18

0.2

0 100 200 300 400 500

Co

effi

cien

t o

f Fr

icti

on

(µ

)

Sliding Distance (m)

PEEK-10% MoAlB(5 runs)

averaged µ

Pure PEEK 0.048

PEEK-10% Cr2AlC 0.079

PEEK-10% MoAlB 0.058

0

0.025

0.05

0.075

0.1

0.125

0.15

Co

effi

cien

t o

f Fr

icti

on

(µ

) Average of All Runs

(5 runs)

F-24 Fuel, Load: 20 N

1.0E-07

1.0E-06

1.0E-05

1.0E-04

1.0E-03

1.0E-02

Wea

r R

ate

(mm

3/ N

*m)

Load (N)

Wear under Ethanol Lubrication

Pure PEEK

PEEK-10% Cr2AlC

PEEK-10% MoAlB

5 20101.0E-07

1.0E-06

1.0E-05

1.0E-04

1.0E-03

1.0E-02

Wea

r R

ate

(mm

3/ N

*m)

Load (N)

Wear under F-24 Lubrication

Pure PEEK

PEEK-10% Cr2AlC

PEEK- 10% MoAlB20

• PEEK-10% MoAlB – Negligible wear under ethanol lubrication at a 5 N load

– Lowest wear under ethanol lubrication at 20 N

• Pure PEEK – Least wear under ethanol lubrication at 10 N

• Wear with F-24 fuel greater than with ethanol

[1] Qu, J. et al. (2005). Wear, 259(7-12), 1031-1040.

[2] S. Ghosh, st al. (2016). Journal of Engineering Tribology

Photo credit: Nikhil Murthy

Manufacturing ProcessA B C D E

PEEK Powder90 vol% PEEK

10 vol% MAX/MAB

Pure PEEK PEEK-10%

Cr2AlC

A. Scale – Measure appropriate amount of

powders

B. Ball mill – Mix powders for 5 minutes

C. Cold press – Press the powders in a 1-inch die

at 210 bar for 30 secs, twiceD. Hot press – Green body is press at 500 °C and

about 117.3 MPa

E. Rotary polisher – Substrate is polished to a

surface roughness of less than 1 µm

UND Advisor: Dr. Surojit Gupta

Assoc. Prof. of Mechanical Engineering

University of North Dakota