Microstructure and Performance of Multi-dimensional WC-CoCr Coating Sprayed by HVOF

• 作 者: Xiang Ding Xudong Cheng Chao Li Zhangxiong Ding Chengqing Yuan
• 机 构: State Key Laboratory of Advanced Technology for Materials and Processing, Wuhan University of Techno
• 出 处: 第十一届全国表面工程大会暨第八届全国青年表面工程学术会议
• 发表日期: 2016年4期
• 关键词: WC-CoCr coatings high velocity oxy-fuel spray microstructure performance

　　WC based coatings deposited by high velocity oxy-fuel spraying (HVOF) have been widely used in many fields which are subjected to severe abrasive wear, such as shipping, metallurgy, energy source, and construction industry to improve the wear resistance and prolong the service life of the components. Much attention has been especially paid to nanostructured and multimodal WC based coatings as a result of their excellent resistance to abrasive wear in recent years. In this study, a new kind of multi-dimensional WC-10Co4Cr coating, which is composed of nano, submicron, micron WC particles and CoCr alloy, was developed by high velocity oxy-fuel spray. The microstructure of the coating was investigated by optical microscopy (OM), scanning electron microscopy (SEM), tran mission electron microscopy (TEM) and X-ray diffraction (XRD). Furthermore, the porosity, microhardness, fracture toughness and electrochemical properties of the coating were measured in comparison with nanostructured WC-10Co4Cr coating sprayed by HVOF. Also abrasive wear resistances of coatings of the multi-dimensional and nanostructured WC-10Co4Cr coatings were evaluated on wet sand rubber wheel abrasion tester. The results show that the multi-dimensional coating possesses dense microstructure, excellent mechanical and electrochemical properties. The porosity, microhardness, fracture toughness and potentiodyn mic potential of the multi-dimensional coating are 0.31±0.09%, 1126±115HV0.3, 4.66±0.51MPa/m1/2 and -0.31±0.02V respectively. Moreover, the multi-dimensional coating presents higher abrasive wear resistance and its wet abrasive resistance is enhanced approximately 36% than the nanostructured coating. The superior abrasive wear resistance of multi-dimensional WC-10Co4Cr coating originates from the coatings multi-dimensional structure, excellent mechanical and electrochemical properties.