滑动模式对超高分子量聚乙烯摩擦磨损行为的影响

在自行研制的髋关节模拟试验机上,以交叉滑动及单向滑动2种方式对比考察了蒸馏水润滑条件下超高分子量聚乙烯(UHMWPE)的摩擦磨损性能,采用扫描电子显微镜观察分析了UHMWPE的磨损表面形貌并探讨其磨损机理.结果表明:在相同载荷条件下,UHMWPE在交叉滑动方式下的磨损率明显高于单向滑动方式;在交叉滑动方式下,UHMWPE的主要磨损机制为磨粒磨损、粘着磨损及塑性变形引起的表层剥落,而在单向滑动下其磨损形式主要为磨粒磨损伴随着少量的疲劳剥片;不同滑动方式所导致的磨损机理差异是造成UHMWPE磨损性能变化的主要原因.与其它试验方式相比,在髋关节模拟试验机上所得出的试验数据更接近临床观测结果.

Study of Friction and Wear Behavior of Ultrahigh Molecular Weight Polyethylene in Different Sliding Model

Friction and wear behavior of Ultrahigh Molecular Weight Polyethylene (UHMWPE) was comparatively examined with a hip joint simulator. Wore surface morphology of UHMWPE was analyzed with a scanning electron microscope. The results show that wear rate of UHMWPE in multidirectional sliding model was higher than that in rotating model. In multidirectional sliding model, wear mechanisms were abrasive wear, adhesive wear and flaking resulting from plastic deformation. Wear mechanisms were mainly scuffing and light flaking due to fatigue in rotating model. Wear rate varied in different test environments because wear mechanism varied with test models. The hip joint simulator can evaluate wear behavior of prosthetic effectively.