GRAIN SHAPE EFFECT IN SUPERPLASTIC DEFORMATION
超塑变形中的晶粒形状效应

The effects of grain shape on the accommodation velocity of grain boundary sliding, which is the dominant mechanism in superplastic deformation, on the contribution of each mechanism to the total strain and the region transition strain rate have been discussed. A new concept, critical aspect ratio for superplas- ticity, has been proposed. The results predicated by means of the new concept were compared with those experimentally observed in an Al-Zn-Mg alloy.