Ti6Al4V合金表面激光沉积复合涂层的组织和性能

Microstructure and property of laser metal deposition composite coating on Ti6Al4 Valloy surface

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。

Wear-resistant composite coatings were fabricated on substrate of a titanium alloy Ti6A14V by laser metal deposi- tion （LMD） process using Cr2C3, WC and Ti powders in order to enhance the tribological properties of Ti6A14V. The micro- structure of the coatings was characterized and the coating microhardness was tested. And their wear resistance was evaluated un- der room-temperature dry-sliding wear test conditions. The results show that the two kinds composite coatings have fine micro- structure consisting of in-situ TiC particles and the unmelted WC particles uniformly distributed in the matrix and are metallurgi- cally bonded to the titanium substrate. The coatings exhibit excellent wear resistance due to the rapidly solidified fine microstruc- ture 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.