In the present study, a novel silicon-aluminizing diffusion coating composed of uniform Ti (Al, Si)₃ phase was manufactured on γ-TiAl alloy via post heat-treatment of cold-sprayed Al-40Si (wt.%) coating. The high temperature oxidation resistance of the diffusion coating was evaluated under 950 ^◦C for 1000 h. During the oxidation process, Ti₅Si₃ precipitations with network-like structure were shaped in the inner of the diffusion coating, which acted as getters for Ti and promoted the formation of Al₂O₃ scale. Meanwhile, an in-situ Ti₅Si₃ diffusion barrier was also formed, which inhibited the interdiffusion between the coating and substrate, especially the fast depletion of Al in the diffusion coating and thus improved the long-term oxidation resistance of γ-TiAl. The microstructure evolution, formation of the in-situ diffusion barrier and high temperature oxidation resistance mechanisms of the diffusion coating were discussed in detail.

在本研究中，通过冷喷涂Al-40Si（wt.%）涂层的后热处理，在γ-TiAl合金上制备了一种由均匀Ti（Al，Si） _{3相组成的新型硅铝化扩散涂层。}扩散涂层的高温抗氧化性在 950 ^° C 下 1000 小时进行了评估。在氧化过程中，扩散涂层内部形成了网状结构的Ti ₅ Si ₃析出物，作为Ti的吸气剂，促进了Al ₂ O ₃氧化皮的形成。同时，原位 Ti ₅ Si ₃还形成了扩散阻挡层，抑制了涂层与基体之间的相互扩散，特别是扩散涂层中Al的快速耗尽，从而提高了γ-TiAl的长期抗氧化性。详细讨论了扩散涂层的微观结构演变、原位扩散阻挡层的形成和高温抗氧化机制。