Different stages in the continuous microstructural evolution of copper deformed to ultrahigh plastic strains

The strain-induced continuous microstructural evolution of pure Cu (99.97%) was recorded in an archeological fashion in a single sample by inducing a high-gradient strain. Quantitative measurements revealed a coupled behavior with obvious inflection points for the variations of critical structure parameters (boundary spacing and misorientation) with strain, separating the microstructural evolution into different stages. The results were discussed by considering the different roles of intragranular dislocation activities and grain/subgrain rotation in the microstructural refinement of metals deformed to high plastic strains.