ICME guided design of heat-treatable Zn-modified Al–Mg alloys

Abstract Currently, there is a tendency towards breaking through conventional 5000 series aluminum alloys framework and designing heat-treatable Al–Mg based alloys with the improved mechanical properties. Here, based on a small amount of experimental work and our previously developed Integrated Computational Materials Engineering (ICME) framework, the authors systematically and efficiently optimize the Zn content and two-step aging treatment process in the heat-treatable Al–Mg–Zn alloys. It is found that the addition of 3.0 wt.% Zn can lower the nucleation activation energy, promote the precipitation of the T phase, and thus enhance and accelerate the age-hardening response of Al–Mg–Zn alloys. Different from the single-step aging process, the pre-aging treatment leads to a large number of fine and dispersive T precipitates due to the precipitation of numerous, stable and dispersive precursors. Further, we optimized two-stage aging treatment for the Al-5.1Mg-3.0Zn alloy which enables the peak-aged yield strength to increase by 21.1% as compared to that in the single-step aging process. This research presents an efficient strategy to design new-generation aluminum alloys via combining the key experimental data and an ICME framework.