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采用5kW横流CO2激光器,在TC4钛合金表面熔覆TiC、TiB2与Ni的混合粉末,制备了无气孔、无裂纹、组织均匀致密的复合涂层。用SEM、EDS、XRD、显微硬度计以及立式万能摩擦磨损试验机分析了激光熔覆层的显微组织、成分和物相,测试了激光熔覆层横截面显微硬度,以及覆层耐磨性能。结果表明,激光熔覆复合涂层与基体呈冶金结合;熔覆层组织从表层到结合区呈现出由棒状、块状向树枝状、颗粒状转变的趋势,且主要由Ti、TiC、TiB、Ti2Ni、TiNi等相组成;熔覆层显微硬度最高可达863HV0.2,为基体的2.5倍;熔覆层耐磨性能较TC4钛合金明显提高。
A 5kW cross-flow CO2 laser was used to melt the mixed powders of TiC, TiB2 and Ni on the surface of TC4 titanium alloy to prepare a composite coating with no pores, no cracks and uniform structure. The microstructure, composition and phase of the laser cladding layer were analyzed by SEM, EDS, XRD, microhardness tester and vertical universal friction and wear tester. The microhardness of the laser cladding layer was tested, Wear resistance. The results show that the laser cladding composite coating is metallurgically bonded with the substrate. The microstructure of the cladding layer changes from rod to block to dendritic and granular form from the surface to the bonding zone, and mainly consists of Ti, TiC, TiB, Ti2Ni, TiNi and other phases. The microhardness of the cladding layer is up to 863HV0.2, which is 2.5 times that of the matrix. The wear resistance of the cladding layer is obviously higher than TC4 titanium alloy.