Al-4Cu-Mg合金的半固态变形及模型化研究

Deformation Behavior and Modeling of Semi-solid Al-4Cu-Mg Alloy

研究了变形温度和应变速率对Al-4Cu-Mg合金半固态变形行为的影响。实验结果表明:变形温度和应变速率对峰值应力影响显著,对稳态应力影响较小。在变形初期,变形主要以液相的流动(LF)和液固相混合流动(FLS)为主,在液相重新分布以后,变形主要以固相粒子的相互滑移(SS)和固相粒子的塑性变形(PDS)来实现,此阶段容易发生液固相分离现象。以半固态热模拟压缩实验为基础,建立了反映半固态Al-4Cu-Mg合金变形行为的本构关系模型,通过验证可知该模型具有较好的精度。

Effects of deformation temperature and strain rate on deformation behavior of semi-solid Al- 4Cu-Mg alloy were investigated. The results show that deformation temperature and strain rate are significant effect on peak stress of Al-4Cu-Mg alloy rather than steady flow stress, which result from different deformation mechanism. At the beginning of compression, the deformation mechanism is liquid flow （LF） and flow of liquid incorporating solid particles （FLS）. However, with the increasing of height reduction, sliding between solid particles （SS） and plastic deformation of solid particles （PDS） are dominating in the semi-solid compression. On basis of the experimental data of semi-solid Al-4Cu-Mg alloy, a model was established to describe the relationship between the processing parameters and flow stress, which shows good match with experimental data.