超音速火焰喷涂WC-10Co4Cr粒子沉积状态对涂层滑动磨损的影响

Effect of WC-10Co4Cr particles splats deposition state on sliding wear behavior of HVOF-sprayed coatings

采用超音速火焰喷涂(HVOF)工艺制备微米结构的WC-10Co4Cr涂层。研究了超音速火焰喷涂过程中粒子沉积状态对涂层干滑动摩擦的影响。采用扫描电子显微镜(SEM)观察颗粒撞击基体时的变形形貌和摩擦磨损后的涂层表面形貌,利用能量X射线色谱仪(EDS)分析变形颗粒和涂层表面不同磨损区域的成分。结果表明,成分均匀的粉末颗粒因受热不同而颗粒铺展形貌不同,受热充分的粉末铺展完全,在摩擦中形成均匀磨损的平整区,受热不充分的粉末铺展不完全,摩擦过程中易发生WC晶粒脱落,形成划痕区,未熔颗粒易在摩擦过程中脱落;成分不均匀的粉末以及合金相多的粉末颗粒铺展完全,摩擦中易形成CoCr合金膜;硬质相多的粉末铺展不完全,易产生孔隙。

In this paper,the micro-structured WC-10Co4Cr coating is prepared by the supersonic flame spraying(HVOF)process,and the effect of particle deposition state on the dry sliding friction of the coating during the HVOF spraying process is studied.A variety of measurement methods are used to detect the structure and performance of the coating.Scanning electron microscope(SEM)is used to observe the deformation morphology of particles when the particles hit the substrate and the surface morphology of the coating after friction and wear.The energy dispersive X-ray spectrometer(EDS)is used to analyze the composition of the deformed particles and the different wear areas on the coating surface.The results show that the powder particles with uniform composition have different spreading morphology due to uneven heating,and the powder with sufficient heating spreads completely and forms uniform wear zone in friction.While the powder is not fully heated,the WC grains are easy to fall off and form scratch zone,and unmelted particles are easy to fall off during the friction process.In this process,it is easy to produce CoCr alloy film in friction because the powder with non-uniform composition and more alloy phases are completely spread.The powders with more hard phases are not spread completely and are prone to pores.