Du Zhihao, Deng Zanshi, Cui Xiaohui, Xiao Ang
College of Mechanical and Electrical Engineering, Central South University, Changsha 410083, China.
Light Alloy Research Institute, Central South University, Changsha 410083, China.
Materials (Basel). 2021 Aug 30;14(17):4954. doi: 10.3390/ma14174954.
High-strength 7075 aluminum alloy is widely used in the aerospace industry. The forming performance of 7075 aluminum alloy is poor at room temperature. Therefore, hot forming is mainly adopted. Electromagnetic forming is a high-speed forming technology that can significantly improve the forming limit of difficult-to-deform materials. However, there are few studies on electromagnetic hot forming of 7075-T6 aluminum alloy. In this study, the deformation behavior of 7075-T6 aluminum alloy in the temperature range of 25 °C to 400 °C was investigated. As the temperature increased, the sheet forming height first decreased, then increased. When the forming temperature is between 200 °C and 300 °C, η phase coarsening leads to a decrease in stress and hardness of the material. When the forming temperature is between 300 °C and 400 °C, continuous dynamic recrystallization of 7075 aluminum alloy occurs, resulting in grain refinement and an increase in stress and hardness. The results of numerical simulations and experiments all show that the forming height and deformation uniformity of the sheet metal are optimal at 400 °C, compared to 200 °C.
高强度7075铝合金广泛应用于航空航天工业。7075铝合金在室温下的成形性能较差。因此，主要采用热成形。电磁成形是一种高速成形技术，能够显著提高难变形材料的成形极限。然而，关于7075-T6铝合金电磁热成形的研究较少。在本研究中，对7075-T6铝合金在25℃至400℃温度范围内的变形行为进行了研究。随着温度升高，板材成形高度先降低后升高。当成形温度在200℃至300℃之间时，η相粗化导致材料应力和硬度降低。当成形温度在300℃至400℃之间时，7075铝合金发生连续动态再结晶，导致晶粒细化以及应力和硬度增加。数值模拟和实验结果均表明，与200℃相比，板材在400℃时的成形高度和变形均匀性最佳。
