High temperature interaction of Y <sub>4</sub>Al <sub>2</sub>O <sub>9</sub>/Y <sub>2</sub>O <sub>3</sub> under CMAS exposure: Mechanism of outstanding corrosion resistance through composition design to accelerate reaction-induced CMAS consumption
Jie Li, Luchao Sun, Tiefeng Du, Yang Cui, Jialin Li, Jing Jing Wang
Abstract
The search for new materials with reliable molten calcium-magnesium-alumino-silicate (CMAS) resistance at elevate temperatures holds important significance for the development of advanced aeroengine. In the present study, a novel Y<sub>4</sub>Al<sub>2</sub>O<sub>9</sub>/Y<sub>2</sub>O<sub>3</sub> composite was designed and fabricated in dense sample using the hot-pressing method. The interactions and mechanisms between Y<sub>4</sub>Al<sub>2</sub>O<sub>9</sub>/Y<sub>2</sub>O<sub>3</sub> composite and CMAS at 1300 ℃ and 1500 ℃ for durations of 1 h, 4 h, 25 h, and 50 h were thoroughly explored. The results reveal that Y<sub>4</sub>Al<sub>2</sub>O<sub>9</sub>/Y<sub>2</sub>O<sub>3</sub> exhibits substantial resistance to CMAS infiltration at both temperatures, without notable grain-boundary penetration by CMAS glass. More importance, the incorporation of reaction active compositions in the composite accelerated the consumption of molten CMAS constituents and reduce its corrosive activity, which is recognized as the crucial principle for composition design of anti-CMAS materials. This work provides valuable insights that guides the design of composition and advancement of superior CMAS-resistant materials.