具有γ/γ’共格组织的Co-Al-W基合金具有良好的高温力学性能，是制造燃气涡轮发动机等动力装置热端部件的理想高温结构材料之一，但高温抗腐蚀性差是制约其工程应用的主要瓶颈问题，迫切需要开展其表面高温防护涂层的研究。本项目针对新型钴基合金表面Al-Si-Dy高温防护涂层, 拟研究包埋渗工艺参数对Al-Si-Dy共渗涂层相组成、形貌、成分分布及生长动力学的影响规律，阐明涂层的组织形成机理；研究Al-Si-Dy涂层的高温腐蚀热力学与动力学、氧化膜的组织结构、氧化膜的生长机制及粘附性，揭示涂层的抗高温腐蚀机理，研究互扩散导致Al-Si-Dy涂层与基体界面组织结构的演化，建立钴基合金与涂层扩散反应动力学模型；研究环境因素及涂层与基体的互扩散对Al-Si-Dy共渗涂层服役寿命影响规律，揭示涂层的失效机理及主要影响因素，为发展钴基高温合金表面具有良好抗高温防护涂层材料与结构的涉及理论与方法奠定基础。

Cobalt-based superalloys with a γ/γ′microstructure are great potential structural materials for aero-engine blades due to their good mechanics properties. However, a major barrier to the high temperature applications of the Co-Al-W alloys is their poor oxidation resistance. Therefore, it is required to investigate high temperature corrosion behavior and failure mechanism of the coating on the Co-Al-W alloys. The aim of this study is to investigate effect of pack cementation parameters on phase constitution, morphology, composition distribution and growth kinetics of Al-Si-Dy coating, formation mechanism for the microstructure of the coating will be revealed. Corrosion thermodynamics and kinetics of the coating, oxide microstructure, oxide growth mechanism, as well as adherence, will be investigated. Oxidation and corrosion resistant mechanism of the coating will be explored. The impact of mutual diffusion on microstructural evolution at the interface between the coating and the substrate will be explored, and the diffusion-reaction kinetics model will be set up.At last, effects of environmental factors and interdiffusion on lifetime of the coating are investigated. The coating failure mechanism and the major effect factors are clarified. This project lays the foundation for developing the material and structure design theory and method for the protective coating on novel Co-based alloys.