2003 年 53 巻 7 号 p. 302-308
The grain refinement of AZ31 magnesium alloy sheet was attempted by giving various plastic deformation to improve press formability. As a result, no grain refinement was attained in uniaxial and biaxial tension deformation, but the remarkable refinement was achieved in shear and compression. The effect of the grain refinement on the bulging formability was examined. Although the forged sheet with fine grain could not be bulged at temperatures between room temperature and 150°C, it could be bulged at above 200°C. Compared to the as-rolled sheet with coarse grains, the forged sheet could be formed at 100°C lower temperature to get the same bulge height.