CoMoCrNi真空熔覆涂层的组织和性能研究

Study on Microstructure and Properties of CoMoCrNi Coating Prepared by Vacuum Cladding

为了提高38CrMoAl钢基体的耐磨抗蚀性能,以CoMoCrNi合金粉末为研究对象,将其与特制的粘结剂混合后涂覆在38CrMoAl钢基体材料表面,通过真空熔覆制备了CoMoCrNi涂层,通过XRD、SEM及其附带的EDS仪、硬度测试、磨粒磨损试验、酸性盐雾试验和电化学腐蚀试验考察了涂层的组织及综合性能。结果表明:制备的CoMoCrNi涂层表面平整,具有金属光泽;涂层由Co基固溶体和Co3Mo2Si硬质Laves相构成,且组织细小均匀致密;CoMoCrNi涂层与基体间形成牢固的冶金结合。基体/涂层的显微维氏硬度呈梯度分布规律,涂层内存在弥散分布的硬质相,其显微硬度远高于基体。CoMoCrNi涂层的耐磨性和耐腐蚀性均高于基体材料。此外,与目前主流的激光熔覆、堆焊等表面加工技术制备的自熔性钴基合金涂层相比,真空熔覆法制备的CoMoCrNi涂层表现出更加优异的耐磨抗蚀性。涂层的综合承载能力更强,可望应用于复杂工况中。

For improving the wear resistance and corrosion resistance of 38CrMoAl steel substrate,CoMoCrNi alloy powder was used as the research object to be mixed with a special binder and coated on the surface of 38CrMoAl steel substrate,and subsequently,the CoMoCrNi coating was prepared by vacuum cladding.The structure and comprehensive performance of the coating were investigated through XRD,SEM and its accompanying EDS instrument,hardness test,abrasive wear test,acidic salt spray test and electrochemical corrosion test.Results showed that the as-prepared CoMoCrNi coating had the smooth surface with metallic luster.The coating was composed of Co-based solid solution and Co3Mo2Si hard Laves phase,and the structure was fine,uniform and dense.In addition,a strong metallurgical bond was formed between the CoMoCrNi coating and the substrate.The micro-Vickers hardness of the substrate/coating exhibited a gradient distribution pattern,and there were dispersed hard phases in the coating,which had a much higher microhardness than the substrate.The wear resistance and corrosion resistance of CoMoCrNi coating were higher than those of the base material.Furthermore,compared with the self-fluxing cobalt-based alloy coatings prepared by current mainstream surface processing technologies such as laser cladding and surfacing welding,the CoMoCrNi coating prepared by the vacuum cladding method showed better wear resistance and corrosion resistance.In general,the coating possessed a stronger comprehensive load-bearing capacity,which could be expected to be used in complex working conditions.