A systematic analysis of the calcium-magnesium-aluminosilicate corrosion behavior of high-entropy (5Re0.2)2Si2O7 materials

The CaO-MgO-AlO1.5-SiO2 (CMAS) corrosion resistance of disilicates is an urgent task in environmental barrier coatings. Based on this, four high-entropy rare earth disilicates (Yb0.2Y0.2Lu0.2Sc0.2Gd0.2)2Si2O7, (Yb0.2Tm0.2Lu0.2Sc0.2Gd0.2)2Si2O7, (Yb0.2Tm0.2Lu0.2Sc0.2Er0.2)2Si2O7, and (Yb0.2Y0.2Lu0.2Ho0.2Er0.2)2Si2O7 and single-component Yb2Si2O7 for comparison were investigated. Results showed that cyclosilicate Ca3RE2(Si3O9)2 and apatite Ca2RE8(SiO4)6O2 are formed sequentially at 1300 ℃ for 48 h, which can block the CMAS from infiltrating the ceramics. The corrosion resistance of the four high-entropy rare earth silicates varied depending on the average RE3+ radius, but all performed better than Yb2Si2O7.