First-principles calculations of structural, elastic and electronic properties of second phases and solid solutions in Ti–Al–V alloys

Abstract The mechanical and electronic characters of the second phases and solid solutions in Ti-xAl-yV (x = 5.0–7.0 wt %; y = 3.5–6.0 wt %) alloys were investigated in detail via first-principles calculations based on density functional theory (DFT). Firstly, the contents of α(AlTi3) and β(Ti–V) phase in goal alloys were calculated. Furthermore, their structural and elastic properties were calculated. Besides, the supercell models of the four solid solutions (Ti32Al4V2, Ti31Al5V2, Ti35Al5V2, and Ti30Al4V2) were established based on the content of β phase in the selected alloys, and then their corresponding structural, elastic and electronic properties were calculated. The computational results for the solid solutions showed that Ti30Al4V2 might present the strongest resist deformation capacity and Ti31Al5V2 might own the largest stiffness. These four solid solutions are all ductile and the directional covalent bonding leads to better stability of Ti35Al5V2 and Ti30Al4V2.