硬质颗粒对等离子熔覆碳化钨/多主元合金复合硬面涂层组织与耐磨性能的影响

Effects of hard particles on microstructure and wear-resistance of plasma cladding WC/multi-principal components alloy composite hard facing coating

采用等离子熔覆技术制备分别以铸造WC颗粒和烧结WC-Co球粒为硬质颗粒、以多主元合金为黏结相的2种硬面复合涂层,采用X射线衍射仪、扫描电镜、摩擦实验等手段,研究不同硬质颗粒对硬面复合涂层组织和耐磨性能的影响。结果表明:FeCrNi/WC-Co复合涂层中M6C的体积分数为20.1%,低于FeCrNi/WC复合涂层中M6C的体积分数(28.4%)。烧结WC-Co颗粒的热力学稳定性高,其WC的溶解程度低于铸造WC颗粒,可有效减少脆性M6C碳化物的析出。FeCrNi/WC-Co复合涂层的耐磨性能优于FeCrNi/WC涂层。FeCrNi/WC-Co涂层中较少的M6C相可避免涂层因脆性断裂而过早剥落,保证硬质相颗粒的完整性,提升硬面涂层的耐磨性能。

Two kinds of hardfacing composite coatings with cast WC particles and sintered WC-Co particles as hard particles and multi principal alloy as bonding phase were prepared by plasma cladding technology.The effects of different hard particles on the microstructure and wear resistance of the hardfacing composite coating were studied by means of X-ray diffraction,scanning electron microscopy and friction experiments.The results show that the volume fraction content of M6C in FeCrNi/WC-Co composite coating(20.1%)is lower than that in FeCrNi/WC composite coating(28.4%).The sintered WC-Co particles have high thermodynamic stability,and the dissolution of WC is lower than that of cast WC particles,which can effectively reduce the precipitation of brittle M6C carbides.The wear resistance of FeCrNi/WC-Co composite coating is better than that of FeCrNi/WC coating.Fe Cr Ni/WC-Co coating with less M6C phases can avoid premature peeling of the coating due to brittle fracture,ensure the integrity of hard phase particles,and improve the wear resistance of the hardfacing coating.