用于热障涂层的锆酸钆材料研究进展

为了满足新型航空发动机的性能要求,需要开发出能在超高温条件下服役的热障涂层材料.近年来已有多种陶瓷材料被证实在热障涂层领域具有发展前景,在这之中,稀土锆酸盐材料有着高温下热导率较低与稳定性良好的特点,其中又以锆酸钆材料的热导率最低,热膨胀系数最高.概述了锆酸钆材料的结构特点,对其在高温下发生的有序无序转变进行了介绍,总...

Research Progress on Gadolinium Zirconate Materials for Thermal Barrier Coatings

In order to meet the performance requirements of new aero-engines, it is necessary to develop thermal barrier coating materials that can be used under ultra-high temperature conditions. In recent years, there are many ceramic materials that have been proved to be promising in the field of thermal barrier coatings. Among these materials, the rare earth zirconate has the characteristics of low thermal conductivity and good stability at high temperature, while the zirconate gadolinium has the lowest thermal conductivity and the highest thermal expansion coefficient. The structural characteristics of zirconate gadolinium materials were overviewed. The order-disorder transition at high temperature was introduced and the reasons and change rules were summarized. The reasons why the zirconate gadolinium had good thermal properties compared with other materials were also briefly analyzed. Two methods commonly used in powder preparation process which named solid phase method and liquid phase method were summarized. On this basis, the research status of different preparation methods and the process both parameters of powder agglomeration in recent years were concluded. Finally, the defects of zirconate gadolinium in the application of thermal barrier coatings were put forward, such as the lower fracture toughness and thermal expansion coefficient, leading to the difficulty in forming single-layer zirconate gadolinium coatings and the lower thermal cycle life. In order to solve this problem, the modification methods of zirconate gadolinium and thermal barrier coatings at home and abroad were reviewed, including the doping modification, the material composite, the coating structure design and the coating preparation technology. At the same time, the development trend of new thermal barrier coatings materials combined with the advanced preparation technology was prospected.