Influence of transition metal on the mechanical and thermodynamic properties of IrAl thermal barrier coating

Although IrAl is a fascinating thermal barrier coating, the improvement of overall performances of IrAl coating is still a big challenge. Here, we apply the first-principles calculations to study the influence of alloying elements on the Vickers hardness, elastic and thermodynamic properties of IrAl coating. Five alloying elements: Cr, Nb, Mo, W and Re are considered. The results show that these elements are stable in IrAl coating. The Re-doped IrAl is more thermodynamic stability than the TM-doped IrAl. The Vickers hardness of Cr-dopant and Re-dopant is 13.2 GPa and 13.4 GPa, respectively, which are larger than the IrAl coating. The Debye temperature of Cr-dopant and Re-dopant is 433.5K and 428.2K, which are also larger than the IrAl coating. The high mechanical properties are that these elements (Cr and Re) improve the localized hybridization between Ir and Al. Hence, we believe that alloying elements of Cr and Re not only enhance the mechanical properties but also improve the thermodynamic properties of IrAl coating. •The influence of alloying elements on the mechanical and thermodynamic properties of IrAl is studied.•We find that these alloying elements are stability in IrAl coating.•We find that alloying elements of Cr and Re can enhance the Vickers hardness of IrAl.•We find that Re element can improve the shear deformation resistance and elastic stiffness of IrAl.•We find that alloying elements of Cr and Re improve the thermodynamic properties of IrAl.