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以亚微米级WC/Co金属陶瓷复合材料为涂层材料,采用激光合金化技术在9CrSi表面制备出硬度高、耐磨的合金化层。利用扫描电子显微镜(SEM),X射线衍射仪(XRD)等分析测试手段对激光合金化层的显微组织和物相构成进行了分析,并对合金化层进行了硬度和摩擦性能测试。结果表明,激光合金化层与基材形成了良好的冶金结合。激光合金化层可分为合金化区,热影响区和基体区三部分。其中合金化区组织为基体马氏体上分布着网状枝晶碳化物,网状枝晶间弥散分布着碳化物小颗粒,热影响区组织由马氏体及残留奥氏体组成,基体区组织无明显变化。合金化层的显微硬度达到900HV0.2,干摩擦条件下材料磨损量是基材9CrSi的1/9,合金化涂层的耐磨性得到显著的提高。
A submicron WC / Co cermet composite was used as the coating material, and the alloying layer with high hardness and wear resistance was prepared on the surface of 9CrSi by laser alloying. The microstructure and phase composition of the laser alloying layer were analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The hardness and tribological properties of the alloyed layer were tested. The results show that the laser alloying layer and the substrate formed a good metallurgical bond. Laser alloying layer can be divided into alloying zone, heat affected zone and the base area of three parts. Among them, the alloying zone is composed of matrix dendritic carbides distributed on the matrix martensite and small carbide particles dispersedly distributed between the dendritic dendrites. The microstructure of the heat-affected zone consists of martensite and retained austenite, No significant change in the organization. The microhardness of the alloyed layer reaches 900 HV0.2, the wear amount of the material under dry friction is 1/9 of that of the substrate 9CrSi, and the abrasion resistance of the alloyed coating is remarkably improved.