Ti6Al4V合金表面激光沉积复合涂层的组织和性能

为了增强Ti6Al4V钛合金的耐磨性，采用激光沉积制造方法在其表面上制备了以原位生成的TiC颗粒和直接添加的WC颗粒为增强相的耐磨涂层，观察了各涂层的微观组织，并测量了涂层的显微硬度和涂层在室温大气条件下的摩擦磨损性能。结果表明各涂层和基体呈现冶金结合，原位自生的TiC和部分熔化的WC颗粒均能够均匀弥散分布于基体上，由于增强相颗粒的弥散强化及激光沉积组织的细晶强化作用，基材的硬度和耐磨性均得到了提高。原位自生的TiC涂层比WC涂层硬度梯度分布平缓，但耐磨性稍差。

Microstructure and property of laser metal deposition composite coating on Ti6Al4V alloy surface

Wear-resistant composite coatings were fabricated on substrate of a titanium alloy Ti6Al4V by laser metal deposition (LMD) process using Cr2C3, WC and Ti powders in order to enhance the tribological properties of Ti6Al4V. The microstructure of the coatings was characterized and the coating microhardness was tested. And their wear resistance was evaluated under room-temperature dry-sliding wear test conditions. The results show that the two kinds composite coatings have fine microstructure consisting of in-situ TiC particles and the unmelted WC particles uniformly distributed in the matrix and are metallurgically bonded to the titanium substrate. The coatings exhibit excellent wear resistance due to the rapidly solidified fine microstructure and the presence of a large amount of in-situ TiC and WC phase. The coating with TiC reinforced phase has better hardness gradient and slightly lower wear resistance than the coating with WC particles.