铝合金板材热塑性变形行为研究

摘要

为了研究铝合金板材的热塑性变形行为，进行了热态胀形试验，获取了不同温度及压力率下的胀形压力－高度曲线，分析了压力率对胀形高度的影响规律。基于同一压力率、不同温度下胀形压力与等效应变之间的关系，提出胀形压力关于等效应变及压力率的拟合方程，同时获得压力率和应变率之间的函数关系。试验结果表明，板材充液热成形工艺过程中，压力率对金属材料的变形行为影响显著，同时压力率能够表征材料成形过程中的变形快慢。%In order to investigate the thermoplastic deformation behavior of aluminum alloy sheet, warm bulging test is conducted to obtain bulging pressure⁃height curves with different temperatures and pressure rates. Then the influence of pressure rate on bulging height is summarized. Based on the relation between pressure rate and strain rate under the same pressure rate and different temperatures, the fitted equation of bulging pressure on equivalent strain and pressure rate is proposed. The functional relation between pressure rate and strain rate is also obtained. The results of warm hydraulic bulging experiments indicated that the pressure rate, which has a significant effect on the deformation behavior of metal material, can characterize the deformation speed in the process of warm sheet hydroforming.