6061-T6铝合金板材热冲压成形极限图研究

Study on Forming Limit Diagram of Hot Stamping of 6061-T6 Aluminum Alloy Sheet

自行设计并研制了一套获取板材热冲压成形极限图的试验系统,开展了6061-T6铝合金板材在不同应变路径及温度下的成形极限研究,获得了其在25~300℃的成形极限图。使用MSC.MARC软件对6061-T6铝合金板材的热冲压成形进行数值模拟,研究了失稳判断方法对不同温度下成形极限预测的影响。结果表明:6061-T6铝合金在室温下的极限应变值很低,塑性较差;变形温度升高到200℃时,极限应变值平均提高了99.5%;变形温度从200℃升高到300℃时,极限应变值进一步提高了23.5%,其塑性也显著提高。采用最大载荷判断法和应变路径判断法相结合的失稳状态判断准则能准确预测6061-T6铝合金的热成形极限,模拟结果和试验结果吻合较好。

A set of test system was designed and developed to obtain the forming limit diagram of sheet hot stamping. The forming limit of 6061-T6 aluminum alloy sheet under different strain paths and temperatures was studied, and the forming limit diagram of sheet in 25-300 ℃ was obtained. The numerical simulation of hot stamping of 606 1-T6 aluminum alloy sheet was carried out by using MSC. MARC software and the influences of instability judgment method on the prediction of forming limit at different temperatures were studied. The results show that the limit strain value of 606 1-T6 aluminum alloy at room temperature is low and the plastic is poor. When the deformation temperature increases to 200 ℃, the limit strain value increases by 99.5%. When the deformation temperature increases from 200 ℃ to 300 ℃, the limit strain value further increases by 23.5%, the plastic also significantly improves. The criterion of instability state which combines the maximum load estimation method with the strain path method can accurately predict the thermal forming limit of 6061-T6 aluminum alloy. The simulation results are in good agreement with the experimental results.