超音速火焰喷涂技术制备的双峰WC–CoCr涂层磨粒磨损特性

采用超音速火焰喷涂(high velocity oxy-fuel,HVOF)工艺分别制备了双峰结构和常规结构的WC–CoCr复合涂层。比较了不同结构WC–CoCr涂层的组织结构、显微硬度和断裂韧性;在涂层磨粒磨损实验的基础上,探讨了双峰结构WC–CoCr涂层的磨损机理。结果表明:与常规结构的WC–CoCr复合涂层相比,在由含质量分数30%超细WC粉末制备的双峰结构涂层中,WC在黏结相中溶解最多,断裂韧性最低;由含质量分数50%超细WC粉末制备的双峰结构涂层最致密,显微硬度与断裂韧性最高,耐磨粒磨损性能最优良。

Abrasive wear behavior of bimodal WC-CoCr coatings sprayed by high velocity oxy-fuel

WC-CoCr composite coatings in bimodal and conventional structures were deposited by high velocity oxy-fuel (HVOF),respectively.The microstructure,microhardness,and fracture toughness of the coatings with different WC particle size distributions were studied,the coating abrasive wear characteristics were carried out by dry-sand rubber wheel abrasion tester,and the wear failure mechanisms of the coatings were investigated.The results show that,the bimodal structure coating fabricated by the powder containing 30wt％ ultrafine WC particles demonstrates the most dissolution of WC in binder during deposition and the lowest coating fracture toughness.However,the bimodal structure coating fabricated by the powder containing 50wt％ ultrafine WC particles combines the least porosity,the greatest microhardness and fracture toughness,and the most superior wear resistance.