奥氏体不锈钢因低硬度和较差耐磨性限制了其应用，故改善不锈钢表面性能对于促进其应用有重要的工程意义。利用激光熔覆技术制备了不同质量分数(0,20%,40%)的MoSi2增强Co基合金的复合涂层。采用扫描电镜(SEM)、X射线衍射仪(XRD)、电子探针显微分析仪(EPMA)等方法研究了MoSi2的添加量对复合涂层的显微组织、相组成、硬度和摩擦磨损性能的影响。结果表明：MoSi2的加入使复合涂层显微组织柱状晶向等轴晶和平面树枝晶转变，且具有细化组织的效果；随着MoSi2含量的增加，Co基复合涂层的显微硬度和耐磨性能也随着提高。当MoSi2的含量为40%时，MoSi2/Co基复合涂层的显微硬度高达1 455HV0.2,磨损率为6.9×10-5 mm3/(N·m);在凝固过程中形成的硬质相(Cr5Si3、MoSi2、Mo5Si3和Co2Mo3)和(Fe、Cr、Co)Si2新型固溶体显著提高复合涂层的耐磨性能；MoSi2增强Co基合金涂层的磨损机制随着MoSi2含量的增加发生转变，即由磨粒磨损、黏着磨损和塑性变形的协同作用转变为黏着磨损、脆性微断裂和氧化磨损。
The application of austenitic stainless steel is limited due to its low hardness and poor wear resistance, and improving the surface properties of stainless steel has important engineering significance to promote its application. In this work, composite coatings of MoSi2 reinforced Co-based alloys with different mass fractions(0, 20%, 40%) were prepared using laser cladding technology. Scanning electron microscope(SEM), X-ray diffractometer(XRD), electron probe microanalyzer(EPMA) and other methods were used to study the effects of the additive amount of MoSi2 on the microstructure, phase composition, hardness and friction and wear properties of the composite coating. Results showed that the addition of MoSi2 changed the microstructure of the composite coating from columnar crystals to equiaxed crystals and planar dendrites, and had the effect of refining the structure. As the MoSi2 content increased, the microhardness and wear resistance of the Co-based composite coating also increased. When the MoSi2 content was 40%, the microhardness of the MoSi2/Co-based composite coating was as high as 1 455 HV0.2, and the wear rate was 6.9×10-5 mm3/(N·m). Moreover, the hard phases(Cr5Si3, MoSi2, Mo5Si3 and Co2Mo3) and the new solid solution(Fe, Cr, Co) Si2 precipitated during solidification significantly improved the wear resistance of the composite coating. The wear mechanism of MoSi2 reinforced Co based alloy coatings changed with the increase of MoSi2 content, and specifically, it's transformed from the synergistic effect of abrasive wear, adhesive wear and plastic deformation into adhesive wear, brittle micro fracture and oxidative wear.
