Thermal/environmental barrier coating with interface thermal expansion mismatch mitigation layer and preparation method and application thereof

The invention discloses a thermal/environmental barrier coating with an interface thermal expansion mismatch relieving layer and a preparation method and application of the thermal/environmental barrier coating, and belongs to the technical field of thermal protection coating materials. The coating sequentially comprises a Si bonding layer, an RE12O3-2SiO2 environmental barrier coating, an interface thermal expansion mismatch relieving layer and an RE22O3-2MO-11Al2O3 thermal barrier coating from a silicon carbide ceramic-based composite material to the outside, wherein the interface thermal expansion mismatch relieving layer is formed by compounding thermal shrinkage ceramic and RE22O3-2MO-11Al2O3 ceramic. A bonding layer, an environmental barrier coating, an interface thermal expansion mismatch relieving layer and a thermal barrier coating are sequentially deposited on the surface of a pretreated silicon carbide ceramic-based composite material through an atmosphere plasma spraying technology. The coating ef