The effects of pre-strain and subsequent electrically assisted annealing on the mechanical behaviors of two different (Al–Mg and Al–Si–Mg) aluminum alloys during electrically assisted dual stage forming are experimentally investigated. First, a specimen is deformed to a specific pre-strain by uniaxial tension and then automatically unloaded. After that, the pre-strained specimen is subjected to electrically assisted annealing by electric current with a fixed subsecond duration. Finally, the specimen is reloaded until fracture. Experimental results show that application of electric current with a subsecond duration induces electrically assisted annealing to both pre-strained aluminum alloys. The electric current also increases total achievable elongation until fracture during electrically assisted dual stage forming for both aluminum alloys. However, analysis of the stress–strain behavior during reloading and microstructural observations suggest that the quantitative effects of electric current on the post-electrically assisted annealing mechanical behavior and resultant microstructure are strongly dependent on the type of aluminum alloy. With the electric current density of 140 A/mm², a full recrystallization followed by grain growth occurs in the pre-strained Al–Mg alloy specimens. For the pre-strained Al–Mg–Si alloy specimens, the electric current density of 140 A/mm² induces both annealing and solid solutioning. Together, our findings indicate that while electrically assisted annealing is effective at improving the productivity of dual stage forming of an aluminum alloy, the composition of the aluminum alloy should be carefully considered in the design of forming process utilizing the concept of electrically assisted annealing since the beneficial effect was limited for the precipitation hardening 6061-T6 aluminum alloy.

实验研究了预应变和随后的电辅助退火对两种不同的（铝镁和铝硅镁合金）铝合金在电辅助双阶段成形过程中力学行为的影响。首先，样品通过单轴拉力变形为特定的预应变，然后自动卸载。之后，以一定的亚秒持续时间通过电流对预应变试样​​进行电辅助退火。最后，重新加载样品直至断裂。实验结果表明，施加亚秒级持续时间的电流会诱发两种预应变铝合金的电辅助退火。电流还增加了总可达到的伸长率，直到在两种铝合金的电辅助双级成型过程中断裂为止。然而，对重装过程中的应力-应变行为和微观结构观察的分析表明，电流对电辅助退火后的机械行为和所得微观结构的定量影响在很大程度上取决于铝合金的类型。电流密度为140 A / mm^{如图2所示}，在预应变的Al-Mg合金试样中发生了完全再结晶，随后发生晶粒生长。对于预应变的Al-Mg-Si合金试样，电流密度为140 A / mm ^2会引起退火和固溶。综上所述，我们的发现表明，尽管电辅助退火可以有效地提高铝合金的双阶段成形的生产率，但在设计过程中应利用电辅助退火的概念来仔细考虑铝合金的成分，因为沉淀硬化6061-T6铝合金的有益效果受到限制。