超音速火焰喷涂细晶WC-12Co涂层的组织性能  

Microstructure and Performance of Fine Grain WC-12Co Coatings Deposited by High Velocity Oxyfuel Spraying

作　　者：马宁[1,2] 张柯柯[1,2] 尹丹青[1,2] 肖笑[1,2] 叶福兴 MA Ning;ZHANG Keke;YIN Danqing;XIAO Xiao;YE Fuxing(Materials Science&Engineering School,Henan University of Science&Technology,Luoyang 471023,China;Collaborative Innovation Center of Nonferrous Metals,Henan University of Science&Technology,Luoyang 471023,China;School of Materials Science and Engineering,Tianjin University,Tianjin 300354,China)

机构地区：[1]河南科技大学材料科学与工程学院,河南洛阳471023 [2]河南科技大学有色金属共性技术河南省协同创新中心,河南洛阳471023 [3]天津大学材料科学与工程学院,天津300354

出　　处：《河南科技大学学报（自然科学版）》2020年第2期1-5,M0002,共6页Journal of Henan University of Science And Technology:Natural Science

基　　金：国家自然科学基金项目(U1604132,51705137);河南省科技攻关计划基金项目(172102210259)

摘　　要：利用超音速火焰(HVOF)喷涂技术,制备了一种钴质量分数为12%的细晶碳化钨基硬质合金涂层(WC-12Co),研究了涂层的组织结构、相组成和干滑动摩擦磨损行为。研究结果表明:HVOF喷涂的细晶WC-12Co涂层微观组织致密、均匀,WC晶粒尺寸与初始粉末相当,为500~900 nm。涂层主要为WC相和Co相,有少量W2C相。与淬火态GCr15钢环干滑动对磨时,磨损率维持在10^-7 mm^3/(N·m)量级,耐磨性良好,干滑动摩擦因数为0.67~0.76。涂层的主要磨损机制为金属Co相的被挤压、犁削和WC颗粒的剥落。重载时,涂层的磨损机制转化为接触疲劳裂纹扩展,导致局部片层剥离,并伴随着富Co区与对磨环的黏着磨损。A fine crystal WC-based carbide coating with 12%(mass fraction)cobalt was prepared by high velocity oxy-fuel(HVOF)spraying.The microstructure,phase composition and dry sliding wear behavior of the coating were studied.The results show that the microstructure of HVOF sprayed WC-12Co coating is compact and uniform.The grain size of WC is 500~900 nm,which is similar to the initial powder.The coating mainly contains WC phase and Co phase with a small amount of W2C phase.When dry sliding is against the hardened GCr15 steel ring,the wear rate of the WC-12Co coatings is maintained at the level of 10^-7 mm^3/(N·m),which shows good wear resistance of the coatings.The dry sliding friction coefficient is 0.67~0.76.The main wear mechanisms of coatings are extrusion and plowing of metal Co phase,and spalling of WC particles.Under heavy loading,the wear mechanism of coating is transformed into contact fatigue crack growth which leads to local lamellar peeling and the adhesive wear of the Co-rich zone with the grinding ring.

关 键 词：超音速火焰喷涂 亚微米结构 WC-12CO涂层 干滑动摩擦 磨损机制 

分 类 号：TG174.4[金属学及工艺—金属表面处理]