激光熔覆WC/316L复合涂层结构及磨损性能

Laser Cladding WC/316L Composite Coating Structure and Wear Properties

为改善激光熔覆过程中WC增强金属基复合涂层分解与分布不均匀的问题,采用激光熔覆技术制备了50%WC含量的WC/316L复合涂层,分别采用扫描电子显微镜(SEM)、显微维氏硬度计、摩擦磨损试验机表征了熔敷层的组织形貌、硬度与摩擦磨损性能。结果显示,低热输入量可以防止WC颗粒下沉,提升熔覆层厚度方向上的WC颗粒分布均匀性;但WC的平面分布均匀性较差,同时低热输入导致WC颗粒结合较弱,易发生脱落;熔覆过程中,粉末中15%的WC发生分解。研究表明,通过降低激光热输入量,可以制备WC厚度方向较为均匀的复合涂层,提升熔覆层耐磨性,但是需要优化WC平面分布均匀性与WC颗粒结合性能。

In order to improve the problem of uneven decomposition and distribution of WC reinforced metal matrix composite coating during laser cladding,a 50%WC content WC/316L composite coating was prepared using laser cladding technology.The microstructure,hardness,and friction and wear properties of the deposited layer were characterized using scanning electron microscopy(SEM),microscopic Vickers hardness tester,and friction and wear testing machine,respectively.The results show that low heat input can prevent WC particles from sinking and improve the uniformity of WC particle distribution in the thickness direction of the cladding layer.However,the planar distribution uniformity of WC is poor,and low heat input leads to weak bonding of WC particles,making them prone to detachment.During the cladding process,15%of WC in the powder decomposes.Research has shown that by reducing the laser heat input,a composite coating with a more uniform thickness direction of WC can be prepared,improving the wear resistance of the cladding layer.However,it is necessary to optimize in-plane distribution uniformity and the bonding of WC particles.