Enhanced the mechanical and thermodynamic properties of Mo2AlC MAX layered carbide for high temperature applications

Mo₂AlC MAX carbide exhibits multiple properties of refractory metal, ceramics and oxidation resistance, making it a promising high temperature material. However, further enhancing its overall properties will be an important challenge in high temperature industries. To improve its overall properties, the influence of refractory metals on the structural stability, mechanical and thermodynamic properties of Mo₂AlC carbide is systematically studied by using first-principles calculations. The calculated result shows that Mo₂AlC and TM-doped Mo₂AlC carbides are thermodynamic and dynamical stabilities. Importantly, it is found that Re-doped, Ta-doped and W-doped enhance the shear deformation resistance and elastic stiffness of Mo₂AlC carbide. Naturally, the high mechanical properties of TM-doped Mo₂AlC are that the doped refractory metal enhances the electronic interaction between Mo and C atoms at the MoC layered structure, and between Mo and Al atoms at Mo-Al-Mo layered structure, which is demonstrated by the change of MoC bond and MoAl bond. In addition, W-doped slightly improves the thermodynamic properties of Mo₂AlC carbide. Therefore, it is believed that W metal, as a useful element, can improve the mechanical and thermodynamic properties of Mo₂AlC carbide, which provides an important guarantee for the wide applications of Mo₂AlC carbides in future high temperature industrial fields.