2024aluminum alloy with Ag-free is an important precipitation strengthened alloys.TheΩphase can be precipitated by cold rolled at room temperature and duplex ageing.The precipitation mechanisms ofΩphase in 2024 aluminum alloy was explored by transmission electron microscopy(TEM)
energy spectrum analysis and other methods.The results demonstrate that duplex ageing and cold rolled technigue are the effective process to promote the precipitation ofΩphase.The concentration decrease of Mg and a large number of nucleation sites around Tphase are mainly responsible for the precipitation ofΩphase.