中文摘要：

采用激光熔覆技术在W6Mo5Cr4V2高速钢试件表面加工出Ni基WC凸包,分析了激光工艺参数对Ni基WC凸包的影响,观察了试件的金相组织并测试显微硬度,通过摩擦磨损试验对比光滑高速钢试件和Ni基WC凸包高速钢试件的摩擦系数和磨损量,并观察磨损形貌。试验结果表明,与高速钢试件相比,Ni基WC凸包高速钢试件的磨损量和摩擦系数降低,激光熔覆Ni基WC凸包能够有效提高高速钢试件表面的耐磨性能。激光熔覆Ni基WC凸包表面以磨粒磨损为主,凸包间隔区域表面包括磨粒磨损和黏着磨损。激光熔覆Ni基WC凸包的硬度提高,WC颗粒的弥散强化作用以及凸包的散热作用,有助于改善Ni基WC熔覆凸包试件耐磨性。

英文摘要：

Ni-based WC bumps on W6Mo5Cr4V2 high speed steel surface were fabricated with laser cladding technology. Effect of laser cladding process parameters on Ni based WC bumps were analyzed. Microstructures of specimens were observed. Microhardnesses of specimens were measured. Friction and wear tests were carried out. Friction coefficients and wear mass loss of smooth high speed steel specimen and high speed steel with Ni-based WC cladding bumps were compared. The worn morphologies of two specimens were observed. The experimental results show that friction coefficients and wear mass loss of high speed steel with Ni-based WC cladding bumps specimens are less than those of smooth high speed steel specimens. Ni-based WC laser cladding bumps can improve the wear resistance of high speed steel surface effectively. The wear mechanism of laser cladding Ni-based WC bumps surface is abrasive wear. The wear mechanism of bumps interval area includes abrasive wear and adhesive wear. The wear resistance improvement of laser cladding Ni based WC bumps specimens are based on following reasons, hard- ness improvement of laser cladding Ni-based WC bumps, dispersion strengthening effect of WC particles and heat dissipation of cladding bumps.