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采用Nd:YAG激光加工系统,在Cu合金上预置粉末激光熔覆了Ni/WC增强Co基复合涂层。利用X射线衍射、扫描电镜和能谱仪等研究了激光熔覆复合涂层组织、增强体颗粒/Co基合金界面结构和WC溶解行为。结果表明,在Cu合金表面以Ni基合金打底过渡,Ni/WC增强Co基复合层、中间过渡层及铜合金基体形成良好冶金结合。随Ni/WC含量的增加,复合涂层中颗粒相明显增加。涂层中WC基本保持原有多角形态,由于Co基合金熔体的浸润,WC被合金化层包裹。当WC含量增加至40wt%,复合涂层中形成了气孔和裂纹,部分WC分解形成Co3W3C,使熔覆层应力增大而出现裂纹。
Nd: YAG laser machining system was used to pretreat laser cladding Ni / WC Co-based composite coating on Cu alloy. The microstructure of laser cladding composite coating was studied by X-ray diffraction, scanning electron microscopy and energy dispersive spectroscopy to enhance the interface structure and WC dissolution behavior of bulk particles / Co-based alloy. The results show that the surface of Cu alloy with Ni base alloy base transition, Ni / WC enhanced Co-based composite layer, the intermediate layer and the transition metal layer to form a good metallurgical metallurgical bond. With the increase of Ni / WC content, the grain size of the composite coating increases obviously. The WC in the coating basically maintains the original polygonal state, and the WC is surrounded by the alloying layer due to the infiltration of the Co-based alloy melt. When the content of WC increases to 40wt%, pores and cracks are formed in the composite coating, and part of WC decomposes to form Co3W3C, causing the stress of cladding layer to increase and cracks occur.