Characteristics of deformation and recrystallization in an aluminum bicrystal initially with a twin boundary

摘要

Deformation and recrystallization experiments are performed using an aluminum bicrystal specimen with twin boundary at initial orientation, against which both edge and screw dislocations in component crystals are piled up. After deformation to 48 percent strain, deformation bands (DBs) develop in deformed matrixes (DMs) along the grain boundary (GB). The interaction of piled-up dislocations at the GB is discussed from two criteria of stress and dislocation transmissions through GBs. It is found that the screw dislocations are difficult to accumulate excessively at the GB, whereas the edge dislocations are steadily stored at the GB. After annealing of the specimen, coexistence of two kinds of recrystallized grains (RGs) due to the strain induce grain boundary migration (SIBM) and the <111> rotated recrystallization model is recognized. The SIBM RGs take place along the GB. The <111> rotated RGs are formed at the DBs away from the GB. It is considered that the SIBM is caused mainly by the accumulation of edge dislocations. The formation of the <111> rotated RGs can be explained from the <111> rotation recrystallization model and the slip systems with Schmid factor bf zero at the initial orientation.