Effect of reactive elements in MCrAlX bond coat for durability improvement of thermal barrier coatings

Abstract

The effects of reactive elements (RE) in MCrAlX alloy (M: Metals, X: RE) as the bond coat for thermal barrier coatings durability were investigated by both experimental evaluation and density functional theory (DFT) calculations. Cyclic oxidation tests showed that the lifetime of the sample with Y, Hf, and Si as RE displayed approximately twice of the sample with Y only. Furthermore, the interface energies between oxide (α-Al2O3) and bond coat with various RE (Si, Sc, Ti, Y, Zr, Hf, La, and Ce) were calculated by DFT. DFT results indicate that Hf and Si doping effectively reduce the interface energy.