Friction and wear behavior of ultra-high molecular weight polyethylene as a function of polymer crystallinity.
In this study the friction, wear and surface mechanical behavior of medical-grade ultra-high molecular weight polyethylene (UHMWPE) (GUR 1050 resin) were evaluated as a function of polymer crystallinity. Crystallinity was controlled by heating UHMWPE to a temperature above its melting point and varying the hold time and cooling rates. The degree of crystallinity of the samples was evaluated using differential scanning calorimetry (DSC). A higher degree of crystallinity in the UHMWPE resulted in lower friction force and an increase in scratch resistance at the micro- and nanoscales. On the nanoscale, the lamellar structure appeared to affect the observed wear resistance. Reciprocating-wear tests performed using a microtribometer showed that an increase in crystallinity also resulted in lower wear depth and width. Nanoindentation experiments also showed an increase in hardness values with an increase in sample crystallinity.
Kanaga Karuppiah
K S
KS
Department of Mechanical Engineering, Iowa State University, Ames, IA 50011, USA.
Bruck
Angela L
AL
Sundararajan
Sriram
S
Wang
Jun
J
Lin
Zhiqun
Z
Xu
Zhi-Hui
ZH
Li
Xiaodong
X
D001672:Biocompatible Materials / Q000737:chemistry*; D003460:Crystallization / Q000379:methods*; D004548:Elasticity; D017276:Friction; D006244:Hardness; D006358:Hot Temperature; D008422:Materials Testing; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D011095:Polyethylenes / Q000737:chemistry*; D013499:Surface Properties; D014783:Viscosity
D001672:Biocompatible Materials; D011095:Polyethylenes; C111601:ultra-high molecular weight polyethylene