2019 Volume 60 Issue 706 Pages 315-320
To improve the formability of rolled AZ31B magnesium alloy sheets at room temperature, the in-plane direction was restricted by precompression along 0 (rolling direction: RD), 30, 45, 60, and 90° (transverse direction: TD) from the rolling direction of the alloy sheets whose strain levels relative to the transverse direction were either 0.055 or 0.11. To avoid buckling during bending, a special fixture with comb teeth for thin sheet compression has been developed. The strong orientation of the basal rolling texture of the sheet was weakened after in-plane compression, and coarser grains were observed. The stretch formability was also improved. The circumferential strain (εθ ) value was dramatically increased from 0.14 (as-received) to 0.30 (precompressed 11.0%) in Mg specimens. Recrystallization and grain growth occurred in grains with higher deformation energy compared with those having less energy after annealing at 250 °C. The intensity of in-plane anisotropy generated at the flange edge of the drawn product could be controlled to some extent by introducing precompressive strain.