Influence of Composition of TGO on the Thermal Shock Lifetime of Thermal Barrier Coatings with Cold-Sprayed MCrAlTaY Bond Coat

Abstract

This study investigates the influence of thermally grown oxide (TGO) on the lifetime of thermal barrier coatings (TBCs). In the experiments, cold sprayed NiCoCrAlY powder was deposited as the bond coat and plasma sprayed YSZ was deposited as the topcoat. The TBCs were subjected to various treatments to induce different types of TGOs at the bond coat-topcoat interface. Three types of oxide were detected, including spinel, chromium oxide, and alumina. Thermal cycling tests show how the oxides contribute to cracking and spalling in the topcoat layer and how the morphologies and constituents of the oxides can change with time and temperature.