Screening of CMAS corrosion-resistant RE₂SiO₅ for environmental barrier coating application by a high-throughput multilayer stacking method

High-temperature corrosion caused by low-melting-point molten salts known as CMAS poses a critical challenge to hot-section components in gas turbine engines. The screening of CMAS corrosion-resistant RE₂SiO₅ ceramics is crucial for the development of environmental barrier coatings for SiC fiber reinforced SiC composites. Due to varying experimental methods, conditions, and CMAS corrosion evaluation approaches, there has been some controversy regarding the CMAS resistance of RE₂SiO₅ ceramics. To address this issue, we employed a high-throughput multilayer stacking method to eliminate external influences such as experimental conditions. The CMAS resistance of several rare earth silicate ceramics was investigated, which revealed the influence of rare earth elements on CMAS corrosion. It was found that the smaller the rare earth ionic radius, the less corrosion product formed. Additionally, Er₂SiO₅ exhibited the best CMAS resistance due to the shallowest penetration depth of CMAS. The results indicate that the evaluation of CMAS corrosion resistance of RE₂SiO₅ ceramics requires a comprehensive consideration of the formation ability of corrosion products, dissolution of RE₂SiO₅, and the penetration of CMAS.