激光熔覆制备Ni60-WC-Co复合涂层工艺与性能研究

Study on Technology and Performance of Ni60-WC-Co Composite Coating Prepared by Laser Cladding

目的提高机械设备用06Cr19Ni10钢的性能,采用激光熔覆制备Ni60−WC−Co复合涂层。方法利用X射线衍射(XRD)、扫描电镜(SEM)、显微维氏硬度计和摩擦磨损试验仪,研究了不同激光功率对复合涂层的微观形貌、硬度和耐磨性的影响。结果随着激光功率增大,复合涂层与基体之间紧密结合,致密均匀,球形WC颗粒均匀分布于复合涂层中,硬度、磨损量均先增大后减小;当激光功率过大时,复合涂层中WC颗粒增多,且部分WC颗粒发生热分解,生成的气体产生气孔。复合涂层物相主要由WC、W_(2)C、γ−Ni、FeNi_(3)、FeCr_(0.29)Ni_(0.16)C_(0.06)、CoC_(x)、Co_(3)B_(2)等相组成,复合涂层由顶部的树枝晶、中部的等轴晶和底部的柱状晶组成;当激光功率为1.5 kW时,硬度最高,磨损量最小,耐磨性最佳,磨损表面无明显磨损沟槽,主要呈磨粒磨损。结论最优激光功率为1.5kW,在此工艺下制备的Ni60−WC−Co复合涂层,可以提高机械设备用06Cr19Ni10钢的硬度和耐磨性。

To improve the properties of 06Cr19Ni10 steel for mechanical equipment,Ni60−WC−Co composite coating was prepared by laser cladding.The effects of different laser power on the microstructure,hardness and wear resistance of the composite coating were studied by XRD,SEM,microhardness tester,friction and wear tester.The results show that with the increase of laser power,the composite coating was dense,uniform and closely combined with the matrix.Spherical WC particles are evenly distributed in the composite coating,the hardness first increases and then decreases,and the wear loss first increases and then decreases.When the laser power is too large,WC particles in the composite coating increase,and some WC particles undergo thermal decomposition,the generated gas produces pores.The phase of composite coating is mainly composed of WC、W_(2)C、γ−Ni、FeNi_(3)、FeCr_(0.29)Ni_(0.16)C_(0.06)、CoC_(x)、Co_(3)B_(2) and other phases.The composite coating is composed of dendrite at the top,equiaxed crystal in the middle and columnar crystal at the bottom.When the laser power is 1.5 kW,the hardness is the highest,the wear amount is the smallest,the wear resistance is the best,and there is no obvious wear groove on the wear surface,which is mainly abrasive wear.The optimum laser power is 1.5 kW.The Ni60-WC-Co composite coating prepared under this process can improve the hardness and wear resistance of 06Cr19Ni10 steel for mechanical equipment.