Enhancing calcium–magnesium–aluminosilicate corrosion resistance in high‐entropy rare‐earth disilicates by multicomponent synergistic effects

This work reports the exploration of high‐entropy rare‐earth disilicates (HEREDs) with exceptional calcium–magnesium–aluminosilicate (CMAS) corrosion resistance at 1673 K through multicomponent synergistic effects. To be specific, 24 variants of HERED‐ x RE (RE = Gd, Ho, Er, Tm) samples are successfully fabricated via a pressure‐less sintering approach, and their CMAS corrosion resistance at 1673 K is systematically tested. The as‐fabricated HERED‐60Tm samples are found to possess the best CMAS corrosion resistance with a corrosion depth of approximately 320 ± 12 µm at 1673 K for 48 h. Further studies have attributed such an excellent CMAS corrosion resistance to the multicomponent synergistic effects, resulting in the optimized thermodynamic reactivity and favorable diffusion kinetics in the as‐fabricated HERED‐60Tm samples. This work provides new insights into the improved CMAS corrosion resistance of HEREDs by the multicomponent regulation, advancing the development of novel thermal /environmental barrier coating materials.