摘要
采用机械涂层技术在Ti-6Al-4V基体表面沉积HA/Ti复合涂层与功能梯度涂层(FGC),对涂层进行表征,对比其磨损行为和生物相容性。制备复合涂层所用初始粉末为50%Ti(质量分数)和50%HA(质量分数)的混合粉末,而FGC分为两层,分别为75%Ti+25%HA和25%Ti+75%HA(质量分数)。XRD结果表明在沉积过程中没有发生相变。此外,由于原始混合粉末中存在Ti颗粒,在涂层和基体之间形成了结合良好的连续界面,特别是在功能梯度涂层样品中。磨损实验结果显示,非梯度复合涂层的摩擦因数约为0.37,在界面处发生突变,而功能梯度涂层的摩擦因数从0.32增加到0.5,在界面处发生平缓变化。磨损表面的SEM像表明涂层的主要磨损机制为磨粒磨损。生物相容性评价结果显示,FGC样品具有更好的细胞黏附和增殖能力。
Characterization,wear behavior,and biocompatibility of hydroxyapatite(HA)/Ti composite coating and functionally graded coatings(FGCs)deposited on a Ti−6Al−4V substrate by a mechanical coating techniquewere compared.The composite coating was produced using the initial powder mixture of 50 wt.%Ti+50 wt.%HA,while the FGC was deposited by two separate layers containing 75 wt.%Ti+25 wt.%HA and 25 wt.%Ti+75 wt.%HA,respectively.The XRD results exhibited that no phase changed during the deposition process.Moreover,due to the presence of Ti particles in the primary powder mixtures,a continuous interface with a superior bond was formed between the coating and the substrate,especially in the samples coated by the FGCs.The wear test results of the non-graded composite coating showed a coefficient of friction(COF)of about 0.37 with an abrupt change at the interface,while the COF of the FGCs increased from 0.32 to 0.5 with a gentle change at the interface.The SEM images of the worn surfaces indicated the dominance of the abrasive wear mechanism.The biocompatibility evaluations revealed better cell attachment and proliferation of the FGC-coated samples.
