人工髋关节纳米和微米级磨粒的机械性能研究

Investigation of Mechanical Properties of Nano and Submicron-sized Wear Particles from Artificial Joints

关节摩擦副运动过程中产生的磨损颗粒,含有大量详尽而重要的摩擦学信息,反映和代表了置换关节不同的磨损形式和机制。利用原子力显微镜技术的定量纳米力学性能测试模式在纳米尺度对UHMWPE磨粒的机械性能、三维几何轮廓以及表面形貌进行考察,并将不同类型磨粒以及聚乙烯基体材料的各种特性进行对比研究。实验结果显示,纳米级和亚微米级磨粒的弹性模量明显较高,且磨粒表面较为平滑;而微米级磨粒和聚乙烯基体材料的弹性模量较小,磨粒表面较为粗糙。分析认为,微米级磨粒是由于聚乙烯材料宏观尺度上的黏着磨损产生;而纳米级和亚微米级磨粒是由于乙烯材料微观尺度上的磨料磨损产生。该分析结果将有利于进一步了解人工关节材料的磨损机制以及磨粒产生的机制。

The wear particles are important information carriers about microscopic wear mechanisms of artificial hip joint components. Atomic force microscopy （AFM） was used to quantify wear particle topographic features and nano-mechanical properties. The mechanical properties and topographic character of the UHMWPE material indicate that the nano- and submicron-sized particles have a much greater modulus and smoother surface than the micron-sized particles and bulKpolymer samples. These differences reveal that the micron particles are most likely to be produced under macroscopic polymer asperity wear, while the nano- and submicron-sized particles are generated under microscopic polymer asperity wear. These findings provide a deeper understanding of the wear mechanism and processes of wear particle generation.