Tribological behaviour of carbon filled hybrid UHMWPE composites in water Hari Shankar Vadivel, Arash Golchin, Nazanin Emami Biotribology group, Division of Machine Elements, Luleå University of Technology, Sweden
Tribological behaviour of carbon filled hybrid UHMWPE
composites in water
Hari Shankar Vadivel, Arash Golchin, Nazanin Emami
Biotribology group, Division of Machine Elements,
Luleå University of Technology, Sweden
IntroductionMove towards water lubrication
• Water a better option than EALs(Environmentally AdaptedLubricants)• Non toxic, readily available (especially
in aqueous envt.)
• Use of water as lubricantrequires use of special materialsfor shafts, bearing, etc.• Prevalence of boundary lubrication
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http://www.w-program.nu/filer/exjobb/Stina_%C3%85strand.pdf
IntroductionPolymer Based Materials (PBMs)
• PBMs are good candidates for use in boundary lubricated conditions [1-3]– Thermoplastics
– Can follow the substrate deformations
– Self-lubricating property
– PLA, PPS, PE, etc.
• Drawbacks – Viscoelastic deformation, water absorption
– High wear rates
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www.thordonaustralia.com
www.zimmer.com
[1] Clarke & Allen, , The water lubricated, sliding wear behaviour of polymeric materials against steel, Tribology International, 24(2), 109-118,1991 .[2] Rymuza, Tribology of polymers, Archives of Civil and Mechanical Engineering, 7(4), 177-184, 2007.[3] Brostow, Tribology of polymers and Polymer based composites, Journal of Materials Education Vol.32 (5-6): 273 – 290, 2010
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Improvement pathways
Cross linking by radiation
Vitamin E
Polymer Blending
Fillers/
composites
Improvement pathways
• Carbon based• CNTs• Graphene
• Metal particles• Fibers
Hybrid/Multiscale Composites
• Combine both micro and nanoreinforcements
– Ability to functionalize the fillers,Possibility to tailor properties, synergisticeffect.
• Micro and nano HA in UHMWPE combineto give better mechanical properties thaneither of them alone [10]
• Sustained macroscale super-lubricity in combination of Graphene and Nanodiamonds [11]
6[10] Kang et al, Mechanical properties study of micro- and nano-hydroxyapatite reinforced ultrahigh molecular weight polyethylene composites, Journal of App. Poly. Sci , 133(3), 1-9, 2016[11] Berman et al., 2015, Macroscale superlubricity enabled by graphene nanoscroll formation , Research, Vol 348 Issue 6239
• Semi crystalline thermoplastic polymer withMolecular weight usually between 2 and 6million g/mol• High molecular weight imparts toughness
• Superior performance in load bearingsystems where water and non oil basedlubrication is used [4,5] and also inbiomedical applications [7,8]
• Excellent low-speed performance ofRubber/UHMWPE alloy as material formarine stern tube bearings[6]
UHMWPEUltra High Molecular weight Polyethylene
n > 100,000.
7[4] Golchin et al, Tribological behaviour of polymeric materials in water-lubricated contacts, Proc. of the Institution of Mech. Eng. Part J-Journal of Eng. Trib., 227(8),811-825, 2013.[7] Affatato et al, Advanced biomaterials in hip joint anthroplasty, Composites Part B: Engineering, 83, 276-283, 2015.[8] Baena et al, Wear Performance of UHMWPE and Reinforced UHMWPE Composites in Arthroplasty Applications: A Review, Lubricants 2015, 3, 413-436, 2015
1. To design Multiscale composites based on UHMWPE
2. To experimentally investigate the synergistic effect of fillerson tribological performance and properties
Research objectives
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Materials
Designation Composition (wt%)
GO ND SCF
UHMWPE Pure UHMWPE
0.5% GO 0.5 - -
0.5% ND - 0.5 -
10% SCF - - 10
GO + ND + SCF 0.5 0.5 10
GO + ND 0.5 0.5 -
GO + SCF 0.5 - 10
ND + SCF - 0.5 10
1% GO 1 - -
1% ND - 1 -
Particle Average size
Graphene Oxide (GO)
Length/width0.7 – 4 μmProfile0.7-1.2 nm
Nanodiamonds(ND)
Ø 5 nm
Short Carbon Fibers (SCF)
length 100 μm, Ø 7 μm
UHMWPE Ø 30 μm
9D. Berman, A. Erdemir and A. V. Sumant, “Graphene: a new emerging lubricant,”, Materials today, vol 17(1), 31-42, 2014Ullah et al., Reinforcing Effects of Modified Nanodiamonds on the Physical Properties of Polymer-Based Nanocomposites: A Review, Polymer-Plastics Technology and Engineering, 54: 861–879, 2015Chukov et al., Investigation of structure, mechanical and tribological properties of short carbon fiber reinforced UHMWPE-matrix composites, Composites Part B: Engineering, 76, 79-88, 2015
Sonication in ethanol
UHMWPE + Filler
Ball MillingDry/wet
DryingComposite powder
Direct Compression Molding
Manufacturing Process
10[13] E. Enqvist, Carbon Nanofiller Reinforced UHMWPE for Orthopaedic Applications , LTU, 2013
• Pin on disc tribo tests– Time : 20h
– Sliding distance ~ 9400 m
– Counter Surface : Inconel 625 discs
– Load : 88 N
– Contact pressure – 5 MPa
• SEM
• Wettability
• Thermal characterisation– DSC
– TGA
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Measurements and analyses
DiscPolymer pin
LoadWaterLVDT
a = 4.2mm
a
Unfilled UHMWPE-pre milling
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SEM
Unfilled UHMWPE-post milling
50 µm 50 µm
GO + ND + SCF
Post milling
50 µm
X ray Microtomography
Friction Coefficient (μ)
14
• Reduction of μ with addition of GO and ND
• 140 μm PE + GO/ND showed higher FC [14,15]
• GO+ND+SCF displays low μ– 21% reduction compared to
unfilled UHMWPE
Fric
tio
n c
oef
fici
en
t (μ
)
0
0,04
0,08
0,12
0,16
0,2
[14] Golchin et al., An investigation into tribological behaviour of multi-walled carbon nanotube/graphene oxide reinforced UHMWPE in water lubricated contacts, Trib. Int. 95 (2016) 156–161. [15] Villain., Nanodiamond/Ultra-High Molecular Weight Polyethylene Composites for Bearing Applications, report, LTU, 2015
Specific wear rate (SWR) of polymer composites
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• Even though 10% SCF showshigh μ , wear rate is not - SCFcan protect the polymer fromabrasion.
• Low value of GO+ND+SCF –15% decrease from unfilledUHMWPE
• 140 μm UHMWPE+GO hashigher wear rate [14]
[14] Golchin et al., An investigation into tribological behaviour of multi-walled carbon nanotube/graphene oxide reinforced UHMWPE in water lubricated contacts, Trib. Int. 95 (2016) 156–161.
0
0,4
0,8
1,2
1,6
2
Spec
ific
we
ar r
ate
10
-6 m
m3
/Nm
Wear tracks
16200 µm200 µm
SCF+UHMWPE
200 µm200 µm
GO+UHMWPE ND+UHMWPE
GO + ND + SCF + UHMWPE
Wettability
• Hydrophobicity of UHMWPE is an important factor in low wear rate in metal-on-polymer contacts [19]
• All fillers used tend toincrease hydrophobicity
• 11% increase in contactangle for GO+ND+SCF
17[19] A. Golchin, G. Simmons, S. Glavatskih, B. Prakash, Tribological behaviour of polymeric materials in water-lubricated contacts, proc. of the inst. of mech. eng-. part j-journal of engineering tribology 227 (8) (2013) 811–825.
Sl. No.
Sample Mean Contact angle
1 Pure UHWMPE 81.4
2 0.5 wt% GO 82.6
3 1 wt% GO 85.9
4 0.5 wt% ND 89.3
5 1 wt% ND 86.8
6 10 wt% SCF 88.3
7 GO + ND + SCF 90.1
8 GO + ND 88
9 GO + SCF 90.4
10 ND + SCF 89.5
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Contact angle vs. μ
• Higher the contactangle, lower the μ– asdesired.
• GO+ND+SCF exhibitslow wear and lowest μwith good hydrophobicnature.
Differential Scanning Calorimetry
• Crystallinity not affected bymanufacturing process
• Similarly, no effect on meltingpoint
• Note: Crystallinity was improvedwith the addition of smallamount of GO and ND – act asnucleation centers [22,23]
• SCF inhibits chain formation[17]
19
0
10
20
30
40
50
60
70
Cry
stal
linit
y (%
)
[ [17] Enqvist et al., Nanodiamond reinforced uhmwpe: a comparison of dry and wet ball milling manufacturing, Tribology - Materials, Surfaces & Interfaces Volume 8, Issue 1, 2014
Thermo-gravimetric analysis
• Composite GO+ND+SCF has the most delayed temperature points
• Delayed oxidation and consequent degradation [18]
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Thermal stability of polymers
[18] R. J. M. John M. Chalmers, Chapter 10 polymer degradation and oxidation: An introduction, in: Comprehensive Analytical Chemistry, Wiley, 2008, pp. 387–450.
Weight left Label Observation
100 % T0 point just before any temperaturechanges start to occur
95 % T1 temperature for maximumsample mass
90% T2 end of the gradual weight loss
5% T3 rapid degradation ends
≤ 1% T4 sample has achieved completedecomposition
Composite Temperature (˚C) ± Standard deviation
T0 T1 T2 T3 T4
UHMWPE 167±5.5 244±2.8 437±12.1 486±1.41 560±1.6
GO+ND+SCF 210±2.4 248±9.4 426±4 489±10.3 582±4.3
• Manufacturing process has beenoptimized.
• Use of smaller PE particles has a positiveinfluence on performance and properties.
• Inclusion of fillers did not affectcrystallinity
• Thermal stability of polymer compositeswas improved
• Hybrid composite has been prepared andshown to perform well. GO+ND+SCF has
– good hydrophobic nature - 11%increase
– low μ - 21% less than unfilledUHMWPE
– low wear - 15% reduction comparedto unfilled UHMWPE
Concluding remarks
21
22
Thank youContact :
[email protected]å University of Technology
This project was carried out within TRIBOS master (European Master MSc. degree in tribology)
1. Clarke & Allen, , The water lubricated, sliding wear behaviour of polymeric materials against steel, Tribology International, 24(2), 109-118,1991 .
2. Rymuza, Tribology of polymers, Archives of Civil and Mechanical Engineering, 7(4), 177-184, 2007.
3. Brostow, Tribology of polymers and Polymer based composites, Journal of Materials Education Vol.32 (5-6): 273 – 290, 2010
4. Golchin et al, Tribological behaviour of polymeric materials in water-lubricated contacts, Proceedings of the Institution of Mechanical Engineers Part J-Journal of EngineeringTribology, 227(8),811-825, 2013.
5. Markus & Allen, The Sliding Wear of Ultrahigh Molecular-Weight Polyethylene in an Aqueous Environment , Wear 178, 17-28, 1994.
6. Hong-ling Qin, Xin-cong Zhou, Xin-ze Zhao, Jing-tang Xing, Zhi-ming Yan, A new rubber/UHMWPE alloy for water-lubricated stern bearings, Wear, Volume 328, 2015, Pages 257-261, ISSN 0043-1648,
7. Affatato et al, Advanced biomaterials in hip joint anthroplasty, Composites Part B: Engineering, 83, 276-283, 2015.
8. Baena et al, Wear Performance of UHMWPE and Reinforced UHMWPE Composites in Arthroplasty Applications: A Review, Lubricants 2015, 3, 413-436, 2015
9. Sattari et al., Interphase evaluation and nano-mechanical responses of UHMWPE/SCF/nano- SiO2 hybrid composites: A Review, Polymer Testing 38 (2014) 26-34, 2014
10. Kang et al, Mechanical properties study of micro- and nano-hydroxyapatite reinforced ultrahigh molecular weight polyethylene composites, Journal of Applied Polymer Science ,133(3), 1-9, 2016
11. Berman et al., 2015, Macroscale superlubricity enabled by graphene nanoscroll formation, Research, Vol 348 Issue 6239
12. D. Berman, A. Erdemir and A. V. Sumant, “Graphene: a new emerging lubricant,”, Materials today, vol 17(1), 31-42, 2014
13. E. Enqvist, Carbon Nanaofiller Reinforced UHMWPE for Orthopaedic Applications, Thesis, LTU, 2013
14. Golchin et al., An investigation into tribological behaviour of multi-walled carbon nanotube/graphene oxide reinforced UHMWPE in water lubricated contacts, Tribology International95 (2016) 156–161.
15. Villain., Nanodiamond/Ultra-High Molecular Weight Polyethylene Composites for Bearing Applications, report, LTU, 2015
16. Enqvist et al., Nanodiamond reinforced uhmwpe: a comparison of dry and wet ball milling manufacturing, Tribology - Materials, Surfaces & Interfaces Volume 8, Issue 1, 2014
17. Suner et al., Ultra High Molecular Weight Polyethylene/Graphene Oxide Nanocomposites: Thermal, Mechanical and Wettability Characterisation, Composites Part B Engineering2015;78(1):185-191
18. R. J. M. John M. Chalmers, Chapter 10 polymer degradation and oxidation: An introduction, in: Comprehensive Analytical Chemistry, Wiley, 2008, pp. 387–450.
19. A. Golchin, G. Simmons, S. Glavatskih, B. Prakash, Tribological behaviour of polymeric materials in water-lubricated contacts, proceedings of the institution of mechanicalengineers part j-journal of engineering tribology 227 (8) (2013) 811–825.
20. N. W. Khun, H. Zhang, L. H. Lim, C. Y. Yue, Tribological properties of short carbon fibers reinforced epoxy composites, Friction (2014) 226–239
References
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