等离子熔覆高耐磨WC-TiC复合增强涂层研究

Research on Plasma Cladding High Wear-Resistant WC-TiC Composite Reinforced Coatings

利用等离子熔覆技术制备WC和TiC复合增强的镍基涂层,通过XRD、SEM和EDS等分析测试方法对涂层的物相组成、显微结构和摩擦磨损性能进行了研究。结果表明,基于WC、TiC和Ni60的比重互补,可以获得碳化物增强颗粒在上下部弥散均匀分布的WC-TiC/Ni涂层;WC和TiC在等离子熔覆高温熔池中均发生部分溶解,分解产生的W、Ti和C原位反应生成(Ti,W)C,通过异质形核和自发形核两种析出长大方式,分别形成核壳状和规则颗粒状的结晶形貌。WC-TiC/Ni涂层能起到明显的降低摩擦、减少磨损的作用,但其摩擦磨损性能受WC与TiC配比的影响,在两者重量总和为40%、比例为1∶1时,涂层的耐磨损性能最佳,磨损体积仅为基材的13.2%。

The WC and TiC composite reinforced nickel base coatings were prepared by plasma cladding technology.The phase composition,microstructure and friction and wear properties of the coatings were studied by XRD,SEM and EDS.The results show that WC-TiC/Ni coatings with carbide reinforced particles uniformly distributed in the upper and lower parts can be obtained based on the specific gravity complementation of WC,TiC and Ni60.Both WC and TiC are partially dissolved in the high temperature molten pool of plasma cladding,and the decomposed W,Ti and C react in situ to form(Ti,W)C,which forms the crystalline morphology of core-shell and regular granular through heterogeneous nucleation and spontaneous nucleation,respectively.WC-TiC/Ni coatings can significantly reduce friction and wear,but their friction and wear properties are affected by the proportion of WC and TiC.When the total weight of WC and TiC is 40%and the ratio is 1∶1,the wear resistance of the coating is the best,and the wear volume is only 13.2%of the substrate.