Behaviors of alloying element titanium in vanadium: From energetics to tensile/shear deformation

Using first-principles simulation, we investigate the effect of alloying element titanium (Ti) on the mechanical properties of vanadium (V). The ideal tensile strengths of Ti1.85V98.15 and Ti6.25V93.75 alloys in the [1 0 0] direction are 18.6 GPa and 17.5 GPa, respectively. These values are, respectively, reduced by 2.6% and 8.4% in comparison with 19.1 GPa of pure V. This suggests that such alloying effect of Ti on the tensile strength of V appears to be relatively large. The generalized fault energies have been calculated including the unstable stacking energy (γcl) and the cleavage energy (γcl) in a pure V and Ti0.35V99.65 alloy along the most preferable {1 1 0}〈111〉 slip system. Ti can decrease γcl from 1.705 J/m2 to 1.704 J/m2 and simultaneously increase γus from 0.308 J/m2 to 0.311 J/m2 in comparison with the pure V. The ratios of γcl/γus for the pure V and Ti0.35V99.65 alloy are 5.536 and 5.479, respectively. The value is decreased by 1.03%, meaning that the ductility of dilute Ti0.35V99.65 alloy can be slightly reduced in comparison with that of the pure V.