High-temperature cyclic oxidation behavior of Al2O3-YAG composite coating prepared by EPD and microwave sintering

► Al2O3-YAG composite coatings were successfully fabricated by EPD in a seeded boehmite sol and pressure filtration microwave sintering. ► The cyclic oxidation tests demonstrate that both of the oxidation and spallation resistances of coatings were greatly improved. ► The reduction of weight gain and enhanced adherence of TGO are determined by the Al2O3 sealing effect and reactive element effects. ► This composite coating could be considered as a new kind of diffusion barrier in thermal barrier coatings.