CMAS作用下一种LaPO4/YSZ热障涂层高温界面稳定性研究

Thermal barrier coating (TBC) is one of the key technologies for advanced gas turbine engine, and Y2O3 partially stabilized ZrO2 (YSZ) is the state-of-the art material for TBCs. Under service conditions, YSZ TBCs are subject to attack by CaO-MgO-Al2O3-SiO2 (CMAS) deposits, resulting in premature spallation of the coatings. CMAS protection for TBCs has attracted much attention, becoming a hot spot and a challenge for TBC research. Efforts have been made to seek for ceramic materials against CMAS attack. Recently, it has been found that LaPO4 could react with CMAS under high temperature to form an inert crystallized layer, which inhibits CMAS further penetration effectively, suggesting that LaPO4 is a promising CMAS protection material for TBCs. In this proposal, LaPO4/YSZ double-ceramics-layer TBCs are proposed for CMAS protection, investigations are focused on structural design, fabrication science and high temperature stability of the coatings under CMAS conditions, aiming to put forward the design method for plasma spraying LaPO4/YSZ TBCs, and master the fabrication science and the precise control technology for the coating composition. The interface matching behavior of LaPO4/YSZ TBCs with CMAS deposits is investigated, and the CMAS protection mechanism is analyzed. One can believe that the research work based on this proposal would provide theoretical guidelines for developing long lifetime TBCs for advanced gas turbine engine.

热障涂层是先进燃气涡轮发动机的核心关键技术之一。在发动机服役环境下氧化钇部分稳定氧化锆（YSZ）热障涂层由于受到以CaO-MgO-Al2O3-SiO2（CMAS）为主的环境沉积物的侵蚀和损伤，发生早期剥落失效。CMAS防护的问题成为了目前热障涂层领域的研究热点和难点。申请者研究了多种陶瓷材料，近来发现LaPO4与CMAS高温反应形成惰性结晶层，能够有效阻止CMAS进一步渗入，是一种非常有前景的热障涂层表面CMAS防护材料。本项目拟研究LaPO4/YSZ双陶瓷层热障涂层的结构设计、涂层制备科学以及CMAS环境下热障涂层的高温稳定性，提出LaPO4/YSZ热障涂层的设计方法，掌握等离子喷涂涂层制备科学及成分精确控制技术，阐明CMAS作用下LaPO4/YSZ热障涂层的界面匹配机制和热防护机理，为研制出先进燃气涡轮发动机长寿命热障涂层提供理论支撑。

热障涂层是先进燃气涡轮发动机叶片的核心关键技术之一。目前最广泛使用的是氧化钇部分稳定氧化锆（YSZ）热障涂层，但在服役过程中易受环境沉积物（主要成分为CaO-MgO-Al2O3-SiO2，简称CMAS）侵蚀而过早失效。CMAS防护的问题成为了目前热障涂层领域的研究热点和难点。本项目研发了一种抗CMAS腐蚀的纳米结构LaPO4/YSZ双陶瓷层热障涂层，通过对涂层的结构设计以及制备科学、热循环性能、高温界面稳定性进行研究，掌握了LaPO4/YSZ热障涂层的成分结构精确控制技术，阐明了涂层热循环失效机理，明确了高温下熔融CMAS在涂层内的渗入规律以及与涂层的热化学反应机理，掌握了LaPO4/YSZ热障涂层抗CMAS腐蚀机制，为研制出先进燃气涡轮发动机长寿命热障涂层提供理论支撑。