WC-Cu-Ni粉末烧结层的组织与性能研究

Study on microstructure and properties of WC-Cu-Ni powder sintering layer

采用热压烧结法在45钢基体表面制备WC-Cu-Ni烧结层,通过金相显微镜和扫描电子显微镜观察其微观组织,用能谱仪分析成分,分别测试烧结层的密度、硬度、孔隙率和耐磨性能。结果表明:烧结层中出现大量"熔池"相区,组织呈网格状结构;随着Ni含量的增加,烧结层致密度逐步降低,Ni质量分数为90%时,致密度转而提高;随着Ni含量的增加,烧结层硬度先增大后减小,Ni质量分数为50%时,硬度达到最大值76.6HRA,相对耐磨系数5.2;Cu、Ni之间以扩散迁移的方式向单相α固溶体转变,烧结层与基体界面处发生Fe元素扩散,两者呈冶金结合。烧结层表面的磨损机制主要以磨粒磨损为主,粘着磨损为辅。

WC-Cu-Ni sintering layer was prepared on the surface of 45 steel using hot pressed sintering.The microstructure was observed through metallographic microscope and scanning electron microscope,the composition was analyzed by energy spectrum analysis,the density,hardness,porosity and wear resistance of the sintering layer were tested respectively.The results show that there are a large number of weld pool phase region in the sintered layer,the microstructure is grid shaped.With the increase of Ni content,the relative density of the layer decreases,which begins to increase when the mass percent of Ni is 90％.The hardness increases firstly and then decreases with the increase of Ni content,the maximum hardness of 76.6 HRA is achieved when the mass percent of Ni is 50％,and the relative wear resistance coefficient is 5.2.Cu and Ni changes to single α solid melt phase through diffusion migration,there are iron element diffusion between the sintering layer and the interface.The wear mechanism of the layer is mainly abrasive wear added with adhesive wear.