A novel approach to improve the macro-segregation defect and mechanical properties of Al–Mg–Mn aluminum alloys during twin-roll continuous casting

In this paper, the microstructure and properties of Al–Mg–Mn alloy slabs with different thicknesses by twin-roll continuous casting were investigated. Under the twin-roll continuous casting process, the alloy melt conducts directional crystallization due to the near-horizontal heat transfer direction. In this way, the growth direction of the columnar crystal is changed to improve the shape and size of the sump and effectively eliminate the central segregation defect. Additionally, the improvement of segregation defects was more significant with the increase in thickness. As low angle grain boundary content and solution degree increased, the electrical conductivity decreased, the hardness increased, and the phenomenon of hard-soft-hard core-shell was significantly improved.