以钛合金为基底,采用等离子喷涂技术制备含30wt%ZrO_2的羟基磷灰石(HA)生物陶瓷复合涂层。观察了HA/ZrO_2复合涂层的微观形貌,采用UMT-3销盘摩擦试验机重点研究了在牛血清润滑环境中,该复合涂层在不同载荷和转速下的磨损性能,观察涂层磨损表面形貌,分析其磨损机理。结果表明:HA30涂层微观表面覆盖着针片状晶粒,结构致密、均匀。截面以无规则细小的气孔为主,并且ZrO_2中间过渡层分别与HA30涂层、基体的结合界面均实现良好的机械咬合。随着施加载荷的增大,HA30复合涂层的摩擦系数和摩损率都升高,磨损机理由微观剥落转化为剥落磨损。随着销盘转速的增加,涂层的摩擦系数减小,磨损率则是先减小后增加,涂层裂纹萌生、扩展直至最终形成凹坑。
The composite hydroxyapatite(HA) coatings containing 30 wt% of ZrO_2 were prepared on the titanium alloy substrate by plasma spraying method. The microstructure of the composite coatings was investigated before and after the wear test, and the wear behavior and the wear mechanism of the composite coatings were studied with UMT pindisk wear tester applying different loads and rotating speeds under bovine serum environment. The results shows that the microscopic surface of HA30 coatings was compact and homogeneous structure covered with needle flake grain and the cross sections were mainly random tiny pores, and the interfaces between ZrO_2 intermediate transition layer and HA30 ceramic coating or substrate were both of good mechanical occlusion. With the increase of applied load, the friction coefficient and wear rate for HA30 coating increased and the wear mechanism changed from micro-spalling fatigue wear to spalling fatigue wear. While the friction coefficient decreases with the rotational speed of pin-disc, the wear rate decreased first and then increased. The crack initiated, propagated and the pits developed eventually.