Sn-Bi合金介质压力成形下轻质铝板的成形性

Formability of lightweight aluminum sheet under Sn-Bi alloy medium pressure forming

提出了Sn-Bi合金介质压力成形方法,利用Sn-Bi合金介质的热敏感特性,通过温度控制其流变行为,可以改变板材压边区的流动状态,同时可实现板材的无压边成形。采用欧拉-拉格朗日自适应网格建立了有限元模型,分析了Sn-Bi合金介质的厚度对成形板材在成形过程的应力、应变和板材厚度分布的影响。揭示了Sn-Bi合金介质压力成形下抑制起皱、破裂的机理。数值模拟结果与试验结果一致,Sn-Bi合金介质压力成形可改善板材成形应力分布,提升板材成形材料流动均匀性,抑制板材失效,为板材的无余量防皱成形方法提供了理论依据。

The Sn-Bi alloy medium pressure forming method was put forward.By using the thermal sensitivity of Sn-Bi alloy medium and controlling its rheological behavior through temperature,the flow state of the blank holder zone of the sheet can be changed,and the forming without blank holder of the sheet can be realized at the same time.The finite element model was established by using Eulerian-Lagrangian adaptive mesh,and the influence of thickness of Sn-Bi alloy medium on the stress,strain and sheet thickness distribution for the formed sheet in the forming process was analyzed.The mechanism of suppressing wrinkling and cracking under Sn-Bi alloy medium pressure form-ing was revealed.The numerical simulation results are consistent with the test results.The Sn-Bi alloy medium pressure forming can im-prove the stress distribution of sheet forming,improve the flow uniformity of materials in sheet forming,and suppress the failure of sheet metal.It provides theoretical basis for the forming method of sheet without allowance and wrinkle prevention.