First principles calculations for vacancy formation energy and solute-vacancy interaction energy in α-Ti

Knowledge of point defect is essential for the understanding of various processes such as solute diffusion and creep in the materials. In this paper, the vacancy formation energy and the solute-vacancy interaction energy in alpha titanium were calculated using the LMTO-ASA method. The solutes investigated include Al, Si and most of the elements in the fourth row of the periodic table. The vacancy formation energy calculated is 2.11eV. The transition metal elements such as V, Cr, Mn, Fe, Co are repulsive to vacancy except for Sc, while the simple metal elements such as Al, Si, Zn, Ga, Ge, are attractive to vacancy except for Cu. The effects of the solute-vacancy interaction on the solute diffusion in alpha-Ti and creep resistance of alpha-Ti alloy are discussed.