包埋法制备CoCrAlY涂层高温氧化组织和性能研究

Research on High Temperature Oxidation Microstructure and Properties of CoCrAlY Coating Prepared by Pack Cementation Method

采用包埋法在GH586表面制备了Co Cr Al Y涂层,研究了涂层在1000℃下恒温氧化和循环氧化100次后的组织和形貌。结果表明,涂层在1000℃下恒温氧化100 h和循环氧化100次后表现为良好的抗高温氧化性能,涂层表面氧化物主要以氧化铝为主。在高温氧化过程中,扩散层的富Cr（W,Mo）相会优先通过晶界向外层扩散,这些富Cr（W,Mo）析出相有利于抑制基体合金元素向外扩散和发生反应,减小了氧化膜的生长速度,增强了涂层的抗高温氧化性能。

Co Cr Al Y coating was prepared on GH586 surface by pack cementation method. The microstructure and morphology of the coating after isothermal oxidation at 1000 ℃ and cyclic oxidation for 100 times, were investigated,respectively. The results indicate that Co Cr Al Y coating after isothermal at 1000 ℃ for 100 h and cyclic oxidation at 1000 ℃for 100 times exhibits good high temperature oxidation resistance, and the main oxide on the surface of the coating is Al2 O3. In high temperature oxidation process, rich Cr（W, Mo） phase in diffusion layer can preferentially diffuse to the outer by grain boundary. The Cr（W,Mo） rich phase can inhibit matrix alloying elements from outward diffusion and reaction, which can reduce the speed of the growth of the oxide film and enhance the high temperature oxidation resistance of the coating.