Study on CMAS corrosion resistance of Gd2O3-Yb2O3-Y2O3-Nb2O5-ZrO2 composite coating

摘要

The high temperature oxide corrosion of environmental deposits (CaO - MgO-Al2O3-SiO2, CMAS) has become one of the important reasons for the premature failure of thermal barrier coatings (TBCs) on aero-engine turbine blades. The CMAS corrosion attached to the surface of the TBCs will quickly penetrate the coating, causing the martensitic transformation of ZrO 2 in the thermal barrier coating, and a large amount of stress is accumulated inside the coating, which leads to the rapid failure of the coating. In this work, Gd2O3-Yb2O3-Y2O3-Nb2O5-ZrO2 (GYYNZO) composite ceramics was prepared with 8YSZ and Gd2O3, Yb 2O3, Y 2O3 as well as Nb2O5 by ball milling. The GYYNZO composite ceramic coatings were prepared by atmospheric plasma spraying (APS). Gd 2O3, Yb 2O3, Y 2O3 and Nb 2O5 reacted with calcium-magnesium-aluminum-silicate (CMAS) at high temperatur e to form dense composite oxides, which inhibited the corrosion path of CMAS to the interior of the coating, so as to achieve the purpose of resisting CMAS corrosion.