大气等离子喷涂WC-12Co涂层的组织结构与性能研究

Microstructure and performance of WC-12Co coating prepared by APS

采用大气等离子喷涂(APS)方法在45钢基体上制备了WC-12Co涂层。用扫描电子显微镜(SEM)、X射线衍射仪(XRD)对涂层的微观形貌和成分进行了分析;采用显微硬度计和万能试验机分别测定了涂层的显微硬度和结合强度;并用SRV-Ⅳ摩擦磨损试验机测试了涂层的摩擦磨损性能。结果表明:WC-12Co涂层组织均匀致密,在喷涂过程中仅少量的WC发生了氧化分解,生成W_2C和Co_3W_3C相。涂层力学性能优异,结合强度平均值为50.63 MPa,涂层表面平均硬度为85.7 HR15N,截面平均显微硬度为1 053.8 HV0.3。相对于304不锈钢,等离子喷涂WC-12Co涂层具有十分优良的耐磨损性能,在室温(25℃)至300℃范围内,WC-12Co涂层的磨损机制为磨粒磨损。

WC-12Co coating was deposited on steel 45 by atmospheric plasma spraying （APS） process. The micro- structure and phase composition of the coating were analyzed by SEM and XRD, respectively; microhardness tes- ter and universal tester were used to measure the microhardness and bonding strength of the coating, respectively; the friction and wear resistance of the coating were examined using SRV- IV friction wear tester. The results indi- cate that, the WC-12Co coating is dense and uniform, only a small amount of WC decomposes during spraying pro- cess and small amount of W2C and Co3W3C phases are observed in the coating. The coating exhibits high mechani- cal properties, the average bonding strength is 50.63 MPa, the surface micro-hardness of the coating is 85.7 HR15N, and the micro-hardness of cross section is 1 053.8 HVo.3, respectively. Compared with the 304 stainless steel, WC- 12Co coating exhibits excellent wear resistance. Abrasive wear is the major wear mechanism for the coating from room temperature to 300 ℃.