Low-angle grain boundaries in an ordered CuAu alloy

Computer simulation of the structure of a low-angle grain boundary (GB) in the ordered CuAu alloy has been carried out. The [II2] direction was taken as the GB rotation axis and the angle of disorientation was 9°. The interatomic interaction was approximated by the empirical Morse pair potential. The energy of the crystal with the defect was minimized using the vacancy and shear mechanisms of relaxation. The vacancy relaxation was realized by replacing the atoms, which became close to each other at the formation of the GB, by vacancies. The shear relaxation was realized by the method of construction of the γ-surface. It has been shown that GBs have stable and metastable states. The transition from one state to another occurs as the result of diffusion processes. The transition into the metastable state simplifies the shift of one grain relative to another and reduces the strain of the grain boundary sliding.