He Daoguang, Xie Han, Lin Yongcheng, Xu Zhengbing, Tan Xianhua, Xiao Gang
School of Mechanical and Electrical Engineering, Central South University, Changsha 410083, China.
State Key Laboratory of Precision Manufacturing for Extreme Service Performance, Changsha 410083, China.
Materials (Basel). 2023 Sep 26;16(19):6412. doi: 10.3390/ma16196412.
High-temperature forming behaviors of a 7046-aluminum alloy were investigated by hot compression experiments. The microstructural evolution features with the changes in deformation parameters were dissected. Results indicated the formation of massive dislocation clusters/cells and subgrains through the intense DRV mechanism at low compression temperature. With an increase in deformation temperature, the annihilation of dislocations and the coarsening of subgrains/DRX grains became prominent, due to the collaborative effects of the DRV and DRX mechanisms. However, the growth of subgrains and DRX grains displayed the weakening trend at high strain rates. Moreover, two constitutive models involving a physically based (PB) model and a gate recurrent unit (GRU) model were proposed for predicting the hot compression features. By validation analysis, the predicted values of true stress perfectly fit with the experimental data, indicating that both the proposed PB model and the GRU model can accurately predict the hot compression behaviors of 7046-aluminum alloys.
通过热压缩实验研究了7046铝合金的高温成形行为。剖析了微观组织演变特征随变形参数的变化情况。结果表明,在低压缩温度下,通过强烈的动态回复(DRV)机制形成了大量位错簇/胞和亚晶粒。随着变形温度的升高,由于DRV和动态再结晶(DRX)机制的协同作用,位错的湮灭以及亚晶粒/DRX晶粒的粗化变得显著。然而,在高应变速率下,亚晶粒和DRX晶粒的生长呈现出减弱趋势。此外,还提出了两个本构模型,一个基于物理的(PB)模型和一个门控循环单元(GRU)模型,用于预测热压缩特征。通过验证分析,真应力的预测值与实验数据完美拟合,表明所提出的PB模型和GRU模型都能准确预测7046铝合金的热压缩行为。