超音速火焰喷涂WC-10Co4Cr涂层的耐滑动磨损行为

摘要

The micro-structured WC-10Co4Cr coatings were deposited by the high-velocity oxy-fuel (HVOF) spray process. The microstructure and sliding wear behavior of the coatings were respectively characterized by optical microscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD) and sliding wear test. The results show that decarborization of the coating is low by using liquid kerosene as fuel. Only WC and W^C exist in the sprayed coating, while there is no η phase (Co3W3C, Co6W6C) or the soft phase W. The coating is highly densified with porosity as low as about 1% and the microhardness of the coating is 1 322 HV03. The coefficient of friction for WC-10Co4Cr coating (about 0.8) is higher than that for lCrl8Ni9Ti stainless steel (about 0.5) and the volume loss of sliding wear is only 1/146 of that of lCrl8Ni9Ti, indicating the excellent sliding wear resistance performance of the WC-10Co4Cr coating. The failure of the WC-10Co4Cr coating during sliding wear is due to binder phase loss followed by wearing of WC particles.%采用超音速火焰喷涂(HVOF)工艺制备微米结构WC-10Co4Cr涂层,分别采用金相显微镜、扫描电镜(SEM)、X射线衍射(XRD)和滑动磨损设备分析涂层的微观结构和滑动磨损行为.结果表明:采用液体煤油燃料HVOF喷涂的微米结构WC-10Co4Cr涂层的脱碳程度较低,涂层中仅出现WC和W2C相,而无η相(Co3W3C、Co6W6C)以及软相W.涂层微观结构致密,孔隙率约为1％,平均显微硬度为1 322HV03:在相同试验条件下,WC-10Co4Cr涂层的摩擦因数(约0.8)高于不锈钢(1Cr18Ni9Ti)的摩擦因数(约0.5),其滑动体积损失量仪为不锈钢涂层的1/146,具有优异的抗滑动磨损性能.涂层在滑动磨损过程中首先是粘结相的脱落,然后是WC颗粒的磨损.