Abstract
The influence of grain structure on the formability of an AZ31 magnesium alloy rolled sheet was examined by deep drawing for five materials. Each sheet was formed at a drawing speed of 60 mm/min into a cup, which had a square bottom of 50 × 50 mm2, and a maximum depth of 18 mm. It was found that the materials with grain sizes of ≤10 μm could be formed to the maximum depth without cracking, even at the lowest temperature investigated (423 K). Tensile mechanical testing of the rolled sheets revealed that these materials with high drawability also had a high Lankford value at the forming temperature. In addition, the surface roughness at the corners of the deep drawn cup was somewhat reduced in the fine–grained materials. The present results suggest that a magnesium alloy sheet with a fine–grain structure has the potential for deep drawing at relatively low temperatures.
