Periodic crystal lattice rotation in microband groups in a bcc metal

Fe–3mass%Si specimens with a columnar grain structure were deformed in compression at ambient temperature. Groups of microbands were found in the vicinity of a grain boundary. These microband groups are characterized by shear and a periodic change of crystal lattice orientation within distances of 1–2 μm. Furthermore, new grains with a size of 200–300 nm were formed in the microband groups during deformation up to 36% strain. A local lattice rotation model is given that explains the experimental observations.