【摘要】 用扫描电子显微镜(SEM)观察了等离子喷涂WC颗粒增强Ni涂层的显微结构,用X射线衍射法(XRD)测试了不同WC含量下涂层及粘结层表面残余应力,利用摩擦磨损试验机和共聚焦激光扫描显微镜研究了涂层的磨损机制。结果表明:涂层表面残余应力为压应力,且随着WC含量的增加先增大后减小,随着涂层厚度的增加而增大,厚度为1000μm时出现分层失效,热应力对粘结层残余应力的贡献最大。一定幅值的压应力有利于涂层耐磨性的提高,同载荷下磨损量仅为基体的0.135倍,涂层磨损机制主要为磨粒磨损。更多还原

【Abstract】 Microstructure of WC particle reinforced Ni-based plasma-sprayed coating was observed by scanning electron microscope( SEM). Surface residual stress of the coating with different WC content and the bonding layer were tested by X-ray diffraction( XRD) method. Microhardness and wear mechanism of the coating were studied by friction and wear test machine and confocal laser scanning microscope. The results show that the surface residual stress of the coatings are compressive stress and decreased with the increase of WC content. However, residual stress increase with the increase of thickness of coatings and when thickness is 1000 μm,the coating appears delamination failure. The thermal stress is the largest contributive factor to residual stress of the bonding layer. A certain amplitude of compressive stress is beneficial to improve abrasion resistance of the coating. The wear loss of the coating is only about 0. 135 times of that of the substrate under the same loading. The wear mechanism of the coating is mainly abrasive wear.更多还原