高焓等离子喷涂WC-10Co-4Cr涂层的微观组织及其拉伸断裂机理

摘要

WC-10Co-4Cr coating was prepared on the surface of 0Cr13Ni4Mo stainless steel by SQC-100 high enthalpy plasma spray system.The porosity,microhardness,wear resistance,bonding strength of the WC-10Co-4Cr coating were assessed in terms of metallographic testing,friction and wear testing,bonding strength testing and tensile testing.The microstructure of the coating was observed by scanning electron microscopy (SEM),and the composition of the coating was analyzed by X-ray diffraction (XRD).The results show that the porosity of the WC-10Co-4Cr coating was 0.77％,the hardness was 1 210 HV,and the anti-wear property of the coating was 143 timesmore than that of the stainless steel matrix.The coating had good bonding to the matrix,with a bonding strengt h of 72 MPa.The WC-10Co-4Cr coating with dense structure was mainly composed of WC phase and few W2C phase,and the fracture mechanism was transgranular fracture and intergranular fracture.Increasing particle speed and temperature can improve the binding strength of the WC-10Co-4Cro coating.%利用SQC-100高焓等离子喷涂系统在0Cr13Ni4Mo不锈钢基体表面制备了WC-10Co-4Cr涂层;通过金相测试、摩擦磨损试验、拉伸试验,分别评价了WC-10Co-4Cr涂层的孔隙率、显微硬度、耐磨损性能、结合强度;利用扫描电子显微镜(SEM)和X射线衍射仪(XRD)分别观察和分析了WC-10Co-4Cr涂层的微观形貌和成分.结果表明:WC-10Co-4Cr涂层的孔隙率为0.77％,硬度为1 210 HV,耐磨性是基体的143倍,涂层与基体保持着良好的结合,结合强度达到72 MPa;WC-10Co-4Cr涂层结构致密,主要由WC相及少量W2C相组成;WC-10Co-4Cr涂层的断裂主要表现为沿晶断裂和穿晶断裂;提高粒子速率和温度可有效提高WC-10Co-4Cr涂层的结合强度.