Structural stability and generalized stacking fault energies in β Ti–Nb alloys: Relation to dislocation properties

The structural stability and generalized stacking fault energies of the {1 1 2}<1 1 1> and {1 1 0}<1 1 1> slip systems in β Ti–Nb alloys with various valence electron numbers were surveyed by ab initio calculations. The structural stability and unstable stacking fault energies along these slip systems decrease monotonously with reducing valence electron number in these alloys. The structure of the dislocation core indicates there is a strong tendency of for the screw dislocations to split into partials in Ti–25Nb (at.%) alloy.