Abstract
To evaluate the superplastic-forming limit of the AZ31 magnesium alloy, the influence of the occurrence of cavitations, which generated in the material during different loading conditions and superplastic flow on a mechanical characteristic was experimentally examined. As result, it is examined that the cavities area is almost the same under 60% pre-strain for examination temperature and testing speed condition used and the cavity coalescence increases with severing testing condition. The depth of the cavity in the tensile test at elevated temperature is about 6um. The cavities area on surface increase with strain for the uniform elongation, but the difference of depth was not seen. Then the cavities area on surface restricts the permission deformation amount of the super-plastic forming of the used material.
