预变形对7075-T6铝合金时效成形回弹及力学性能的影响

Effect of pre-deformation on springback and mechanical properties of 7075-T6 aluminum alloy during creep aging forming

为评价铝合金预变形-时效成形工艺的可行性,试验研究了预变形对7075-T6铝合金时效成形性能的影响。研究表明:预变形能显著降低7075-T6铝合金的时效成形回弹率,并在一定程度上提高其塑性,但对其拉伸强度产生不利影响。随着预变形程度的增加,合金的屈服强度和抗拉强度降低,初始强化相GP区减少,η'相向粗大η相的转变,并形成较宽的无沉淀析出带,从而弱化其时效成形强度。

In order to evaluate the feasibility of pre-deformation and aging forming process of aluminum alloy,the effects of pre-deformation on creep aging formability of 7075-T6 aluminum alloy sheets were investigated.The results show that the pre-deformation can significantly reduce the springback rate of aging forming of the 7075-T6 aluminum alloy and improve its plasticity to some extent,but it has adverse effect on the tensile strength.With the increasing of pre-deformation degree,the yield strength and tensile strength of the alloy decrease,the GP zone of initial strengthening phase decrease,η＇ phase changes to coarse η phase,and the precipitate free zone is wide,thereby weakening the strength of aging forming of the alloy.