Thermo-mechanical properties and CMAS resistance of (Ho0.4Yb0.3Lu0.3)2SiO5 solid solution for environmental barrier coating applications

Rare earth monosilicate (RE2SiO5) is one of the most promising candidates as an environmental barrier coating (EBC) for SiCf/SiC ceramic matrix composites. But single-component RE2SiO5 is hard to meet the multiple and harsh performance requirements of EBC which brings a significant challenge to their applications. Based on our previous research on single-component RE2SiO5 ceramics, (Ho0.4Yb0.3Lu0.3)2SiO5 solid solution was designed and successfully fabricated in this work. Doping of multiple RE elements endows (Ho0.4Yb0.3Lu0.3)2SiO5 with excellent thermal insulation properties and matched thermal expansion coefficient with SiCf/SiC substrates. In addition, it exhibits lower elastic modulus and comparable hardness than that of single-component RE2SiO5. (Ho0.4Yb0.3Lu0.3)2SiO5 also presents good resistance to calcium-magnesium alumino-silicates (CMAS) corrosion. Rational composition design allows (Ho0.4Yb0.3Lu0.3)2SiO5 to retain the merits of single-component RE2SiO5 while taking advantage of the solid solution effect. The results of this work suggest (Ho0.4Yb0.3Lu0.3)2SiO5 as a promising EBC candidate.

Automated summary

Based on the previous research on single-component RE2SiO5 ceramics, a (Ho0.4Yb0.3Lu0.3)2SiO5 solid solution was designed and fabricated. The doping of multiple RE elements endows (Ho0.4Yb0.3Lu0.3)2SiO5 with excellent thermal insulation properties, matched thermal expansion coefficient with SiCf/SiC substrates, lower elastic modulus, comparable hardness, and good resistance to CMAS corrosion. (Ho0.4Yb0.3Lu0.3)2SiO5 is suggested as a promising candidate for EBC.