Cavity characteristics in a magnesium alloy.

摘要

Magnesium alloys have high potential as structural materials but they generally have poor workability because of the HCP structure. Superplastic forming is one method to improve their formability. On the other hand, cavitation occurs in many kinds of alloys during superplastic flow. Cavity formation causes the materials to fail; therefore it is necessary to investigate cavitation characteristics.; Commercial magnesium alloy AZ31 was used in this work. Tensile tests were conducted and a maximum elongation of 419% was obtained at 723K with a constant strain rate of 2 × 10−5 s−1 . As a result, most of the cavities were close to being round in shape, therefore the cavities were not elongated very much. It is concluded that cavity nucleation occurs frequently but the cavities grow very slowly.