Structural, elastic and electronic properties of B2-type modified by ternary additions FeAl-based intermetallics: First-principles study

The structural, elastic and electronic properties of FeAl (B2) intermetallics modified by ternary additions have been investigated by first-principles calculations based on density functional theory (DFT). The calculations of the formation enthalpy indicate that Al atoms are more easily replaced by the alloying elements X (X = V, Sc, Mn, Si, Mg, Co, Zr, Cu, Zn, Nb, Cr, Mo, W, Ti, Ni). The ratio of the bulk modulus to shear modulus B/G and Poisson's ratio v show that the FeAl-Cr, FeAl-Ti, and FeAl-Co systems are ductile materials and FeAl-Co (B/G = 1.92, v = 0.28) is the most ductile phase among these alloy phases. The electronic structure calculations indicate that the doping by Cr, Ti and Co may lead to the charge redistribution, the weakening of the Al-Al interaction, and strengthening of the Fe-Fe and Fe-Al interactions. It can be concluded that Cr, Ti and Co form the most stable FeAl-based intermetallics.