基体硬度对冷喷涂层组织结构和性能的影响

Effect of substrate hardness on microstructures and properties of cold-sprayed coatings

为分析Co基合金材料用于冷喷涂修复不同硬度基材的可行性,在3种不同硬度的基体材料表面,采用冷喷涂工艺制备了Co基合金涂层,并进行了组织结构、硬度、冲蚀磨损性能以及抗腐蚀性能研究。结果表明:随着基体硬度的增加,Co基合金粉末颗粒变形更加明显;304不锈钢基体表面涂层的孔隙率低于Cu基体和司太立合金基体表面涂层的孔隙率;在司太立合金基体上的喷涂态Co基合金涂层硬度高于其他2种基体涂层的硬度;3种基体表面涂层的盐雾腐蚀和电化学腐蚀性能无明显差异,但其电化学腐蚀性能均优于各基体;Cu基体表面涂层受到30°攻角冲蚀磨损时,其质量损失比其他2种涂层高22%;但在90°攻角冲蚀磨损时,3种涂层质量损失相当;基体与冷喷涂粉末硬度的匹配影响涂层的组织和性能。

To explore the repair probability of substrate with different hardness by Co-based materials for cold spraying,Co-based alloy coatings were deposited on three substrates with different hardness by cold spraying in this study.The microstructure,hardness,erosion and corrosion resistance of cold-sprayed coatings were characterized.The results show that,with the increase of substrate hardness,the deformation of Co-based alloy powder particles is more pronounced.Porosity of coatings sprayed on 304 stainless steel substrate is lower than that of coatings sprayed on Cu and Stellite substrates.Hardness of as-sprayed Co-based alloy coatings deposited on Stellite substrates is higher than that of the other two coatings.The three coatings exhibit similar salt fog corrosion and electrochemical corrosion properties.Moreover,the electrochemical corrosion properties of three coatings are better than three substrates.The erosion weight loss of coating deposited on Cu substrates is 22%higher than other coatings when subjected 30°erosion.The weight losses of three coatings are similar after 90°erosion test.The research results indicate that the matching of substrate with the hardness of cold spray powder affect the microstructure and properties of cold sprayed coatings.