Ma Zheng, Ji Hongchao, Huang Xiaomin, Xiao Wenchao, Tang Xuefeng
College of Mechanical Engineering, North China University of Science and Technology, Tangshan 063210, China.
School of Mechanical Engineering, University of Science and Technology Beijing, Beijing 100083, China.
Materials (Basel). 2021 Sep 22;14(19):5485. doi: 10.3390/ma14195485.
The stress strain curve of 7075 aluminum alloy in the temperature range of 310 °C to 410 °C was obtained by Gleeble-3800. By Nakazima test, the isothermal thermoforming limit diagrams of 7075 aluminum alloy at different deformation temperatures and stamping speeds were acquired. Moreover, the parameters of automotive S-rail hot stamping process were optimized by GA-BP neural network. The results show that the forming limit curve of 7075 aluminum alloy increases as the deformation temperature and stamping speed increase. The predicted optimal parameters for hot stamping of automotive S-rails by GA-BP neural network are: stamping speed is 50 mm/s, friction coefficient between die and blank is 0.1, and blank holder force is 5 kN. The maximum thinning rate at this process parameter is 9.37%, which provided a reference for 7075 aluminum alloy automotive S-rail hot stamping.
通过Gleeble-3800获得了7075铝合金在310℃至410℃温度范围内的应力应变曲线。通过 Nakazima试验，获取了7075铝合金在不同变形温度和冲压速度下的等温热成型极限图。此外，利用GA-BP神经网络对汽车S型梁热冲压工艺参数进行了优化。结果表明，7075铝合金的成型极限曲线随着变形温度和冲压速度的增加而增大。GA-BP神经网络预测的汽车S型梁热冲压最佳参数为：冲压速度50mm/s，模具与坯料之间的摩擦系数0.1，压边力5kN。在此工艺参数下的最大减薄率为9.37%，为7075铝合金汽车S型梁热冲压提供了参考。
