等离子喷涂WC-12Co/NiCrAl复合涂层的摩擦磨损特性

以NiCrAl涂层为粘结层,用等离子喷涂工艺在TC4钛合金表面制备了WC-12Co/NiCrAl复合涂层。通过扫描电镜(SEM)、能谱仪(EDS)、X射线衍射仪(XRD)和显微硬度仪等手段分析了涂层微观形貌、化学成分和显微硬度,并用磨损试验考察了WC-12Co/NiCrAl复合涂层的摩擦磨损特性。结果表明:WC-12Co涂层表面未熔颗粒较多,涂层截面孔隙率为10.2%;WC发生部分分解,出现W2C、Co6W6C等新相;涂层与基体结合界面为机械结合+局部微冶金结合方式;显微硬度为双态Weibull分布,呈现不同位置结构的差异化。WC-12Co涂层表现出良好的减摩及耐磨性能,同载荷下摩擦因数低于基体,磨损失重为基体的1/10,磨粒磨损是其主要磨损机制。

Tribological Properties of WC-12Co/NiCrAl Composite Coating Prepared by Plasma Spraying

WC12Co coating was prepared on TC4 titanium alloy surface by plasma spraying with the NiCrAl coating as the bonding layer. The microstructure, chemical components and microhardness were analyzed by scanning electron microscopy (SEM), energy diffraction spectrum (EDS), Xray diffraction (XRD) and microhardness tester. The tribological properties of WC12Co/NiCrAl composite coating were discussed by the friction and wear test. The results show that the WC12Co coating surface has many unmelted particles and the porosity of the cross section coating is 10.2%. WC particles partly decompose and form new phases of W2C, Co6W6C, etc. The interface combination mode between the coatings and the substrate is mainly mechanical combination and local metallurgical combination. The microhardness of WC12Co coating presents binary Weibull distribution, which shows structure differentiation at different positions. WC12Co coating shows good antifriction performance and abrasive resistance. The friction factor is lower than that of the substrate and the wear volume is only about 1/10 of the substrate. Abrasive wear is the main wear mechanism of the WC12Co coating.