Adjusting the correlation between the oxidation resistance and mechanical properties of Pt-based thermal barrier coating

Although PtAl is an attractive thermal barrier coating (TBC), the key problem is to adjust the correlation between the oxidation resistance and mechanical properties. Here, we apply the first-principle calculations to investigate the oxidation mechanism of PtAl coating and explore the influence of alloying elements(Y, Cr and Si) on the oxidation resistance of PtAl coating. We further study the influence of Cr concentration on the elastic modulus and brittle-or-ductile behavior of PtAl. It is found that 0 prefers to occupy the center of Pt tetrahedron. Compared to Y-dopant, Cr-dopant and Si-dopant enhance the oxidation resistance of PtAl coating because the charge interaction of Cr-O and Si-O is stronger than that of the AI-0 atoms. In particular, the Cr element effectively improves the shear deformation resistance and elastic stiffness of PtAl. With increasing Cr concentration, the formation of Cr-Al bond enhances the elastic stiffness and shear deformation resistance of PtAl. Therefore, our results predict that Cr is a useful element to improve the overall performance of PtAl thermal barrier coating.