Effect of microstructure on CMAS corrosion behavior of (Gd0.8Yb0.2)2Zr2O7/YSZ thermal barrier coatings prepared by EB-PVD

Three types of (Gd0.8Yb0.2)2Zr2O7 (GYbZ)/YSZ double ceramic layer thermal barrier coatings (TBCs) were prepared with different microstructures by electron beam physical vapor deposition. The CMAS corrosion performance of the three TBCs was studied at 1250 ℃ compared with YSZ-TBC. The results showed that the CMAS corrosion resistance strongly depends on their microstructures. TBCs consisting of smaller inter-column gaps and larger specific surface area exhibited superior CMAS corrosion performance. The reaction products of GYbZ-TBCs are mainly composed of Gd-apatite and fluorite c-ZrO2 based fluorite. The effect of microstructure on CMAS infiltration depth was discussed.