MCrAlY金属黏结层高温失效行为研究进展

Research progress in high-temperature failure behavior of MCrAlY metal bond-coat

随着航空发动机与燃气轮机涡轮进口温度的不断提高,MCrAlY(M=Ni,Co或NiCo)包覆型涂层因具有抗高温氧化以及高的热膨胀系数等优点,成为广泛应用的热障涂层金属黏结层材料。然而,高温服役环境下热障涂层中金属黏结层与陶瓷面层界面应力分布状态愈加复杂,黏结层界面失效导致陶瓷面层的剥落,限制了其在热防护涂层领域的发展。本文简述了黏结层的发展进程,重点阐述高温相转变、热应力和生长应力增加以及S元素扩散等因素导致的黏结层界面的失效行为,分析黏结层界面失效机理,归纳总结了国内外针对金属黏结层界面失效的改进研究工作,并在此基础上提出采用稀土及纳米颗粒协同强化MCrAlY材料,为未来热障涂层体系的优化设计提供了研究方向。

The MCrAlY(M=Ni,Co or NiCo)has become a widely used bond-coat material of thermal barrier coatings(TBCs)due to its advantages of high-temperature oxidation resistance and high thermal expansion coefficient,with the continuous increase in turbine inlet temperature of aero engines and gas turbines.However,the stress distribution at the interface between the bond and top coating in thermal barrier coatings becomes more complicated under a high-temperature service environment.The failure of the bond-coat leads to the spalling of the top coating,which limits the development of the thermal protection coating field.The development process of the bond-coat was briefly described.The failure behavior of the bond-coat interface due to high-temperature phase transition,increased thermal and growth stresses,and S-element diffusion was focused on,and the failure mechanism of the bond-coat interface was analyzed.The research on improving the bond-coat interface failure at home and abroad was summarized.The synergistic strengthening of MCrAlY by rare earth and nanoparticles is proposed,which provides a research direction for the future optimization design of thermal bond-coat systems.