为了改进Ti6Al4V钛合金的高温耐磨性能, 采用激光沉积制备技术, 通过改变同步送粉双料仓速率方式, 在Ti6Al4V钛合金表面制备了以WC颗粒为强化相的钛基梯度复合涂层。对耐磨涂层的微观组织进行了观察, 测量了涂层和Ti6Al4V基材的显微硬度和在500 ℃条件下的摩擦磨损性能, 并对涂层的强化机制和磨损机理进行了分析。结果表明: WC颗粒增强相均匀弥散分布在基体中, 并因吸收激光能量的不同而呈现不同的形态。由于WC颗粒和生成的TiC弥散强化及激光沉积基体组织的细晶强化作用, 基材的硬度和耐磨性均得到了提高。在相同的摩擦磨损条件下, 复合涂层较钛合金基材的耐磨性提高了约5 倍。

To improve high temperature wear resistance of Ti6Al4V, titanium matrix gradient composite coating reinforced by WC particles was deposited on Ti6Al4V substrate by Laser Metal Deposition(LMD) process by precisely controlling the delivery of Ti6Al4V and WC powders. The microstructure and worn surface were investigated ,and the microhardness and friction wear properties of the coatings and substrate were examined at 500 ℃. The results show that the WC reinforced phases distribute on deposition layers evenly and the particles melt down partially which shows different morphology and component. Microhardness analysis indicates that the hardness shows gradient ascent from the substrate to the coatings surface, and the wear-resistant of coatings has improved 5 times compared with substrate.High microhardness and good wear resistance are due to the small grain size and dispersion strengthening of unmelted WC and TiC particles generated in LMD process.