Kang Jiajie, Wang Mingzheng, Yue Wen, Fu Zhiqiang, Zhu Lina, She Dingshun, Wang Chengbiao
School of Engineering and Technology, China University of Geosciences, Beijing 100083, China.
National International Joint Research Center of Deep Geodrilling Equipment, Beijing 100083, China.
Materials (Basel). 2019 Jan 18;12(2):301. doi: 10.3390/ma12020301.
This study experimentally investigated the effect of surface textures on the tribological mechanism of nitrided titanium alloy (Ti⁻6Al⁻4V). The titanium alloy samples were nitrided at various temperatures ranging from 750 to 950 °C for 10 h in a plasma nitriding furnace. Then, surface textures were fabricated on the polished titanium alloy and plasma nitrided samples by laser process system. The surface roughness, microhardness, and constitution of samples treated by single nitriding and samples treated by composite technology were characterized. The tribological properties of the samples were investigated on a CSM ball-on-disc tribometer. The results show that plasma nitriding effectively enhances the wear resistance of the substrate. The wear rate decreases first and then increases with the increase of nitriding temperature, and the wear rate reaches the minimum at 900 °C. However, the increase in roughness caused by nitriding treatment leads to an increase in the friction coefficient. It is found that surface textures can obviously reduce the friction coefficient of the nitrided titanium alloy. In addition, it can also reduce the wear rate of titanium alloys after nitriding at 900 and 950 °C. It can be concluded that the nitriding and surface texturing combined treatment can obviously reduce the friction coefficient and wear rate at the nitriding temperatures of 900 and 950 °C. This is attributed to the combined effect of high hardness of nitride layers and the function of micro-trap for wear debris of surface textures.
本研究通过实验研究了表面织构对氮化钛合金（Ti⁻6Al⁻4V）摩擦学机制的影响。将钛合金样品在等离子体氮化炉中于750至950℃的不同温度下氮化10小时。然后，通过激光加工系统在抛光的钛合金和等离子体氮化样品上制备表面织构。对单氮化处理的样品和复合技术处理的样品的表面粗糙度、显微硬度和成分进行了表征。在CSM球盘摩擦磨损试验机上研究了样品的摩擦学性能。结果表明，等离子体氮化有效地提高了基体的耐磨性。磨损率随氮化温度的升高先降低后升高，在900℃时磨损率达到最小值。然而，氮化处理导致的粗糙度增加导致摩擦系数增大。研究发现，表面织构能明显降低氮化钛合金的摩擦系数。此外，它还能降低900℃和950℃氮化后钛合金的磨损率。可以得出结论，在900℃和950℃的氮化温度下，氮化与表面织构复合处理能明显降低摩擦系数和磨损率。这归因于氮化物层的高硬度和表面织构对磨损碎屑的微捕集作用的综合效果。
