【摘要】 采用激光熔覆工艺和电火花沉积工艺在Q235钢上熔覆铁基合金粉末和WC陶瓷硬质合金,形成复合涂层。采用X射线衍射仪、扫描电镜、显微硬度计等对复合涂层的相结构、显微组织、显微硬度及耐磨性能进行了分析。结果表明:复合涂层主要是由Fe3W3C、Co3W3C、Si2W、W2C和(Fe0.51Mn0.46Ni0.03)6C等相组成;复合涂层与基体呈冶金结合,复合涂层中电火花区域中细小的硬质相弥散分布于沉积层中;复合涂层的厚度为140～160μm,其中电火花沉积区域约为40μm,激光熔覆工艺的涂层厚度为100～120μm;电火花沉积层的硬度最高可达1262.9 HV,平均硬度为1151.6 HV,电火花沉积区域与激光熔覆区域之间的过渡区域的显微硬度为884.8 HV,激光熔覆区域的显微硬度平均值为578.3 HV;复合涂层的耐磨性较基体耐磨性提高2.3倍,强化层的磨损机理主要是磨粒磨损、粘着磨损和氧化磨损。更多还原

【Abstract】 A composite coating was produced on the surface of Q235 by electro-spark deposition(ESD) and laser cladding technique.The phases,microstructure and microhardness of the coating were investigated by means of scanning electro microscopy(SEM),X-ray diffractometer(XRD) and microhardness tester.The results show that the composite coating metallurgically bonded with the substrate consists of Fe3W3C、Co3W3C、 Si2W、W2C and(Fe0.51Mn0.46Ni0.03)6C phases.The fine hard phase’s particles distribute dispersedly in the ESD zone.The thickness of the composite coating is 140～160 μm.The thickness of the ESD zone is about 40 μm.The thickness of the laser cladding zone is 140～160 μm.The maximum hardness of the ESD zone is 1262.9 HV0.3.The average hardness of the ESD zone is 1151.6 HV0.3 and the average hardness of the plasma cladding coating is 578.3 HV0.3.The composite coating has improved wear-resistance performance and the average wear-resistance rate is 2.3 times of that of the substrate.The wear mechanism is mainly abrasive wear,adhesion wear and oxidization wear.更多还原