TC4合金氩弧熔覆TiN复合涂层的组织及耐磨性

为提高钛合金表面性能,以TiN粉和Ti粉为原料,利用氩弧熔覆技术,在TC4合金表面成功制备出TiN增强Ti基复合涂层。采用扫描电镜、X射线衍射仪分析了熔覆涂层的显微组织和物相组成;利用显微硬度仪、摩擦磨损试验机测试了复合涂层的显微硬度和室温干滑动磨损条件下的耐磨性能。结果表明:氩弧熔覆涂层组织均匀致密,熔覆层与基体呈冶金结合,熔覆涂层主要由TiN棒状树枝晶和TiN颗粒组成,复合涂层明显改善了TC4合金的表面硬度,涂层的最高显微硬度可达9.5 GPa;复合涂层在室温干滑动磨损实验条件下具有优异的耐磨性,磨损机制主要是磨粒磨损,其耐磨性较TC4合金基体提高近9倍。

Microstructure and wear resistance of TiN composite coating on TC4 alloy by argon arc cladding

Aimed at improving the titanium alloy surface properties, this paper introduces the suc- cessful preparation of Ti-based composite coating reinforced by TiN particle on the surface of TC4 steel, based on argon are cladding technique with the pre-alloyed powder of TiN and Ti. The paper describes an analysis of the mierostructure and phase of the coating using scanning electron microscopy （ SEM）, X - ray diffraction（XRD） and the examination of microhardness and wear resistance at room temperature of the composite coating by means of microhardness tester and wear tester respectively. The results prove that TIG cladding coating behaves in a uniform and compact way as to produce a metallurgical bond be- tween the TC4 steel substrate and the coating consisting mainly of TiN stick-like dendrites TiN particles. The composite coating reinforced by TiN particle affords a significant improvement in surface hardness of TC4 alloy, resulting in the highest microhardness of 9.5 GPa in some cases. The composite coating ex- hibits a better wear resistance under dry sliding wear test conditions than otherwise would occur. The composite coatings shows wear resistance nine times higher than that of TC4 coatings.