Impact of solute-vacancy complex defects on ideal shear strength, stacking fault energy and elastic constants of perfect Ni crystals

Ideal shear strength (σmax), stacking fault energy and elastic constants can provide important information about crystal plastic deformation. By using the first-principles calculation, the effect of point defect (Re, W, Mo and vacancy) and solute-vacancy (Re-Vacancy, W-Vacancy and Mo-Vacancy) complex defects on σmax, stacking fault energy and elastic constants in the perfect Ni crystals at 0 K was investigated, so that their general validity at high temperatures just are indicative. The calculation results indicate that Re-Vacancy, W-Vacancy and Mo-Vacancy complex defects at the four nearest neighboring sites in the perfect Ni crystals are the most preferable configurations. The addition of single-solute (Re, W and Mo) point defects can increase the unstable stacking fault energy, σmax and elastic constants of perfect Ni crystals, and reduce intrinsic stacking fault energy. Therefore, single-solute point defects are beneficial for the reinforcement of perfect Ni crystals. The introduction of either single vacancy defect or Re-Vacancy, W-Vacancy and Mo-Vacancy complex defects into perfect Ni crystals are detrimental to the creep resistance of γ-Ni phase.