Effects of transition metal (Cr, Mn, Mo, Ni, Ti, and V) doping on the mechanical, electronic and thermal properties of Fe3Al

Alloying is one of the main ways to improve the structure and mechanical properties of Fe3Al alloys. Here, first-principles calculations are used to study the influence of alloying elements on the stability and elastic, brittle-or-ductile and thermodynamic properties of Fe3Al. Six alloying elements, Cr, Mn, Mo, Ni, Ti, and V, are considered. The results reveal that these elements are stable in Fe3Al. V-doped Fe3Al has more thermodynamic stability than TM-doped Fe3Al. Importantly, doping Fe3Al with the transition metals Cr, Mo, and Ni can improve the toughness of compounds. The three-dimensional (3D) surface profiles and their planar projections of the Young's modulus for the compounds show significant directional dependence. The total density of states and bond populations are utilized to illustrate the electronic structures and chemical bonding characteristics. The Debye temperature after V-doping is larger than that of Fe3Al alone. Moreover, the sound velocity anisotropy of the compounds is calculated. Therefore, we predict that alloying V not only enhances the mechanical properties but also improves the thermodynamic properties of Fe3Al.