Investigation on the relation of microstructures and CMAS corrosion resistance of high entropy RE disilicates

Three kinds of high entropy (Y0.25Sc0.25Er0.25Yb0.25)2Si2O7, (Y0.2Sc0.2Er0.2Yb0.2Lu0.2)2Si2O7 and (Y0.2Sc0.2Er0.2Yb0.2Gd0.2)2Si2O7 were designed and synthesized in order to investigate the relation of microstructures and CMAS corrosion resistance. At low temperature of 1300 °C, lattice distortion played a crucial role in resistance to CMAS corrosion, and larger lattice distortion contributed to CMAS corrosion resistance. However, the corrosion behavior at 1500 °C was related to the equivalent ionic radius and RE species. The smaller equivalent ionic radius tended to promote the re-precipitation of high entropy RE disilicate in residual CMAS glass rather than apatite. The results will provide theoretical guidance for the microstructural design of high entropy RE disilicate and selection of RE elements in future.