摘要
Rare earth(RE)silicate is one of the most promising environmental barrier coatings for silicon-based ceramics in gas turbine engines.However,calcium-magnesium-alumina-silicate(CMAS)corrosion becomes much more serious and is the critical challenge for RE silicate with the increasing operating temperature.Therefore,it is quite urgent to clarify the mechanism of high-temperature CMAS-induced degradation of RE silicate at relatively high temperatures.Herein,the interaction between RE_(2)SiO_(5) and CMAS up to 1500℃was investigated by a novel high temperature in-situ observation method.High temperature promotes the growth of the main reaction product(Ca_(2)RE_(8)(SiO_(4))6O_(2))fast along the[001]direction,and the precipitation of short and horizontally distributed Ca_(2)RE_(8)(SiO_(4))6O_(2) grains was accelerated during the cooling process.The increased temperature increases the solubility of RE elements,decreases the viscosity of CMAS,and thus elevates the corrosion reaction rate,making RE_(2)SiO_(5) fast interaction with CMAS and less affected by RE element species.
基金
This work was financially supported by the National Natural Science Foundation of China(Grant Nos.52202078 and 52202126)
Guangdong Basic and Applied Basic Research Foundation for Distinguished Young Scholars(Grant No.2021B1515020083)
Guangdong Basic and Applied Basic Research Foundation(Grant Nos.2021A1515110293 and 2022A1515012201)
Shenzhen Science and Technology Program(Grant Nos.202206193000001 and 20220818183014003).
