Ti6Al4V合金表面离子注入N+C,Ti+N和Ti+C性能研究

Characterization of N+C,Ti+N and Ti+C ion implantation into Ti6Al4V alloy

摘要:

采用等离子体基离子注入的方法在Ti6Al4V合金表面分别注入N+C、Ti+N和Ti+C元素，注入剂量均为2×1017 ions/cm2，N+C和Ti+N元素的注入负脉冲偏压为-50 kV，Ti+C元素的注入电压分别为-20 kV、-35 kV和-50 kV。通过X射线光电子能谱仪（XPS）和X射线衍射仪（XRD）对注入层进行了微观结构分析，结果表明：Ti+C注入层中存在TiC和Ti-O，Ti+N注入层中存在TiN和Ti-O键。采用纳米压痕仪和球盘磨损试验机对注入层的硬度和摩擦学性能进行了研究。结果表明：在相同注入电压下，Ti+C注入层的硬度最高，其次是Ti+N注入层，N+C注入层的硬度最低；Ti+C 注入层的硬度随着注入电压的增大而增大，最大硬度为11.2GPa。50kV注入层Ti+C具有最低的比磨损率，其值为6.7×10-5mm3/N.m，比磨损率较未处理Ti6Al4V基体下降了1 个数量级以上，表现出优异的耐磨损性能。

Abstract:

In this paper, TiN and TiC films were prepared on Ti6Al4V substrates by plasma based ion implantation. The effect of N+C and Ti+N hybrid ion implantation at 50 kV, and Ti+C ion implantation at 20 kV, 35 kV and 50 kV on mechanical properties was studied. The implantation was up to 2×1017 ions/cm2 fluence. XPS and XRD were used to characterize the modified surface of the implanted samples. It was found that the modified layer of Ti+C implanted at 50 kV was TiC and Ti-O bond and the layer of Ti+N implanted at 50 kV was TiN and Ti-O bond. The nano-hardness and the friction coefficient were measured by nano-indentation measurements and pin-on-disc-test. Hardness tests have shown that the hardness increased with N+C, Ti+N and Ti+C ion implantation. For Ti+C implanted samples, the hardness was increased with increasing negative voltage. The sample of implanted with Ti+C at 50 kV exhibited the highest hardness of 11.2 GPa. The results of wear tests showed that both Ti+C and Ti+N ion implanted samples had much better wear resistance compared un-implanted sample. The wear rate of Ti+C implanted at 50 kV sample was 6.7×10-5mm3/N.m, which was decreased over one order than un-implanted sample.