High strain rate superplasticity of AZ31 alloy
The superplasticity of coarsed grain AZ31 magnesium alloy was investigated in the temperature range of 623723 K at strain rates from 103 to 101 s1.It is found that with increasing strain rates,the elongation increases firstly,and then reaches the maximum value of 278％ nearly at the strain rate of 5×102 s1.The best superplastic conditions are at 723 K and at the strain rate of 5×102 s1.During superplastic deformation,it is found that the mean grain size decreases from original 30 μm to 18 μm,indicating grain refinement is the dominant process at the initial stage of the superplastic deformation,meanwhile the grains become more homogenous and most of the grains are still equiaxed.However,the size and distribution of deformation cavity vary with deformation conditions at the last stage of deformation.At best superplastic condition,the cavity exhibits homogenous and ball-like.It is indicated that the dominant superplastic deformation mechanism at high strain rate is both grain refinement and grain boundary sliding.
AZ31 magnesium alloy high strain rate superplasticity cavity
ZHOU Hai-tao JIANG Yong-feng ZHONG Jian-wei ZHAO Zhong-kai LI Qing-bo
School of Materials Science and Engineering,Central South University,Changsha 410083,China
国际会议
2007年国际有色金属大会(International Conference of Nonfereous Materials 2007)(ICNFM)
长沙
英文
2007-11-28（万方平台首次上网日期，不代表论文的发表时间）