7075-T6高强铝合金温拉深成形工艺

Warm drawing process for 7075-T6 high strength aluminum alloy

为探究中间温度对厚度为0.3 mm的7075-T6高强铝合金板材拉深成形的影响,采用有限元仿真和实验方法对25~300℃温度区间的拉深件的成形云图、壁厚变化、最大成形高度以及晶粒形貌和尺寸进行分析,获得了成形温度对铝合金筒形件的成形质量和微观组织的影响规律。结果表明:随着成形温度的升高,样件危险区域的壁厚减薄率降低,更易拉深成圆筒形件,最大成形高度呈先增大后减小的趋势,最优成形温度为250℃,此时极限拉深比达到最大值2.31;随成形温度升高,动态回复和动态再结晶软化机制增强,硬度降低,板料塑性得到改善。最大成形高度的有限元仿真与实验结果误差小于2.0%,证明建立的仿真模型可用于7075-T6铝合金拉深成形工艺的参数优化。

In order to explore the influence of intermediate temperature on the deep drawing of 7075-T6 high strength aluminum alloy sheet with the thickness of 0.3 mm,the forming cloud map,wall thickness change,maximum forming height,grain morphology and size of drawing parts at the temperature range of 25-300 ℃ were analyzed by finite element simulation and experiment methods,and the influence laws of forming temperature on forming quality and microstructure of cylindrical parts were obtained.The results show that with the increasing of forming temperature,the wall thickness reduction rate in the dangerous area of sample decreases,and it is easier to draw into cylindrical parts.The maximum forming height increases first and then decreases.The optimal forming temperature is 250 ℃,and the ultimate deep drawing ratio reaches the maximum value of 2.31.With the increasing of forming temperature,the dynamic recovery and dynamic recrystallization softening mechanisms are enhanced,the hardness is reduced,and the plasticity of sheet metal is improved.The error of maximum forming height between finite element simulation and experiment is less than 2.0%,and the simulation model can be used to optimize the parameters of deep drawing process for 7075-T6 aluminum alloy.