Grain boundary evolution of highly nanotwinned alloys: Effect of initial twinned microstructure

Abstract The effects of initial twinned microstructure on the grain growth behavior of four sputtered nanotwinned copper alloys were compared. As-deposited films were characterized by transmission electron microscopy and the microstructural evolution of the annealed samples was investigated through electron backscatter diffraction. Texture showed a pronounced effect, where films with strong {111} textures exhibited abnormal grain growth that was not observed in a randomly textured film. Additionally, the stability induced by twin boundaries appears to be limited, as the excess energy generated by a large twin density could drive the early onset of abnormal grain growth and recrystallization.