中文摘要：

采用电火花沉积技术,在铸铁表面制备WC-8Co沉积涂层。利用XRD、SEM、显微硬度计、摩擦磨损试验机研究了涂层的微观组织及耐磨性能。结果表明,通过优化的沉积工艺参数可以获得组织均匀、致密且与基体呈冶金结合的沉积层。沉积层主要由Co3W3C、Fe3W3C、W2C和Fe7W6相组成;沉积层中弥散分布有大量的超细碳化物颗粒。沉积层的最高硬度为1512.1Hv,其耐磨性能是基体的2.3倍;沉积层的磨损机制主要是磨粒磨损和疲劳磨损。涂层中弥散分布的超细硬质相是沉积层硬度及耐磨性能提高的主要因素。

英文摘要：

The cast iron surface is strengthened with the electrode of WC-8Co cemented alloy using electro-spark deposition（ESD） technique.The microstructure and properties of the coating were investigated by X-ray diffraction,scanning electron microscopy and Vickers hardness tester.The results show that ESD technique can produce dense coating on surface of cast iron with proper process parameters.The coating consists of Fe3W3C,Co3W3C,Fe7W6 and W2C phases,and large superfine carbide particles dispersedly distribute in the coating.The maximum hardness of the coating is 1512.1Hv,and its wear resistance is 2.3 times of the substrate.The wear mechanism includes abrasive and fatigue wear.Superfine hard phases which distribute dispersedly in coating are the main factors leading to high hardness and wear resistance of the coating.