Extremely improved formability of Al-Zn-Mg-Cu alloys via micro-domain heterogeneous structure

Here we report a heterogeneous microstructure in Al-Zn-Mg-Cu alloys by coupling control of solute gradient distribution, multiscale iron-rich phases and a novel thermomechanical processing that can produce a greatly improved formability (the average plastic strain ratio r = 0.719). A heterogeneous structure of coarse grains surrounded by fine grains is formed, and an unusual high formability is obtained by the synergy of soft/hard microdomains. The process discovered here is amenable to large-scale automotive industrial production at low cost, and might be applicable to other Al alloy systems.

Automated summary

In this study, a heterogeneous microstructure in Al-Zn-Mg-Cu alloys was reported, which showed greatly improved formability by controlling the solute gradient distribution and employing a novel thermomechanical processing. The structure consisted of coarse grains surrounded by fine grains, and the synergy of soft/hard microdomains contributed to the unusual high formability.