Effects of Vacuum Induction Melting and Copper Water-Cooled Mould Casting on Thermo-Mechanical Treatment Microstructure and Properties of 2024 Aluminum Alloy

The effects of vacuum induction melting and copper water-cooled mould casting on microstructure and properties of 2024 aluminum alloy after thermo-mechanical treatment were studied using tensile testing, scanning electron microscopy, transmission electron microscopy and optical microscopy. The results show that compared with the conventional casting, the vacuum induction melting and copper water-cooled mould casting can improve the microstructure of 2024 alloy, including increasing the amount of equiaxed grains, refining grains and decreasing the average grain size from 125 μm to 28 μm. The tensile strength and yield strength of the alloy after thermo-mechanical treatment (TMT) prepared by vacuum induction melting and copper water-cooled mould casting reached 603 MPa and 581 MPa, the specific elongation of the alloy was up to 12.0%. The alloy had a good combination match of plasticity with strength. The fracture of conventional casting 2024 aluminum alloy presented brittle fracture mode, but the fracture of vacuum induction melting and copper water-cooled mould casting alloy presented ductile fracture mode.