Super-high formability of Al-5.0Zn-1.5Mg-1.5Cu (wt.%) alloy via gradient heterogeneous structure

Abstract

A novel idea of precisely constructing gradient heterogeneous microstructure was proposed to greatly improve the formability of Al-Zn-Mg-Cu alloy by coupling multi-process firstly. After coupling control of the heterogeneous distribution of precipitates, strain energy storage and dislocation number density, a gradient distribution of coarse/fine grains can be constructed in the pre-aged alloy, resulting in a greatly enhanced average plastic strain ratio of 0.716. This work opens up a new frontier for achieving super-high room temperature formability without sacrificing the high strengths for Al-Zn-Mg-Cu alloys.

GRAPHICAL ABSTRACT

IMPACT STATEMENT

This paper reports a gradient heterogeneous structure in Al-Zn-Mg-Cu alloys by coupling control of precipitates, strain energy storage and dislocation number density, resulting in a greatly enhanced average plastic strain ratio of 0.716.

KEYWORDS:

• Al-Zn-Mg-Cu alloys
• gradient heterogeneous microstructure
• high formability
• mechanism

Data availability

The raw/processed data required to reproduce these findings cannot be shared at this time due to technical or time limitations.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by National Key Research and Development Program of China: [grant no 2021YFE0115900]; National Natural Science Foundation of China: [grant no 51871029, 51571023 and 51301016]; Industry-University Cooperation Collaborative Education Project: [grant no 202102437001, 202102437002]; Government Guided Program-Intergovernmental Bilateral Innovation Cooperation Project: [grant no BZ2019019]; Opening Project of State Key Laboratory for Advanced Metals and Materials: [grant no 2020-ZD02, 2022-Z03].