Dual gradient structure in Al-Zn-Mg-Cu-Fe alloys: A pathway to balancing strength and formability

Abstract

Gradient structures offer a unique synergistic strengthening mechanism that enhances the properties and performance of alloys. In this study we developed a dual gradient structure Al-Zn-Mg-Cu-Fe alloy using a groundbreaking short-process thermomechanical treatment. The process permit to successfully triumph over the traditional strength-formability competition in the alloy, leading to a well-balanced association of them. The gradient structure creates heterostructural interfaces that induce plastic incompatibility during deformation resulting in development of strain gradients. The strain gradients generate additional hetero-deformation induced (HDI) hardening, which aids the alloy to achieve exceptional room-temperature formability (RTF) while maintaining elevated strength.