HVAF制备27SiMn钢WC涂层沉积机理研究

Study on Deposition Mechanism of WC Coating on 27SiMn Steel Prepared by HVAF

以经过喷砂预处理的27SiMn钢为原材料,采用活性燃烧高速空气燃料喷涂技术(AC-HVAF)制备WC-10Co-4Cr涂层。采用SEM与EDS对WC-10Co-4Cr涂层的微观形貌和涂层在基体结合处的沉积机理进行了研究。结果表明,采用HVAF制备的WC涂层十分致密,无明显的裂纹与孔洞缺陷,涂层整体孔隙率为1.4%左右。在HVAF喷涂超音速的作用下,少量WC颗粒直接进入到基体中并形成明显裂纹。涂层与基体主要以机械结合为主,伴随少量的微区冶金结合和扩散。

27 SiMn steel was pretreated with sandblasting as raw material.WC-10Co-4Cr coating was prepared by active combustion high speed air fuel spraying(AC-HVAF).The microstructure and the deposition mechanism of WC-10Co-4Cr coating were studied by SEM and EDS.The results show that the WC coating prepared by HVAF is very dense.There are no obvious cracks and pore defects,and the overall porosity of the coating is about 1.4%.Under the action of supersonic HVAF spraying,a small number of WC particles enter the matrix directly and form obvious cracks.The coating and substrate are mainly mechanically bonded,accompanied by a small amount of microzone metallurgical bonding and diffusion.