Improving element uniformity and mechanical properties of Al-Mg-Si alloy fabricated by twin roll casting with superheat melt treatment

Abstract The effect of superheat melt treatment(SMT) on microstructure and properties Al-Mg-Si alloy fabricated by twin roll casting(TRC) was analyzed using optical microscope, scanning electron microscopy, emission probe micro analyzer transmission microscopy. SMT increased the subcooling degree during TRC. solidification with high dendrite density small spacing obtained. second phase evenly distributed between dendrites solute concentration gradient decreased. Intergranular aggregation caused Reynolds’ dilatancy in TRC slab effectively suppressed. homogeneous distribution can be realized short-time homogenization heat treatment. size insoluble particles greatly reduced. complete decomposition non-equilibrium eutectic α-Al, which promoted precipitation precipitates aging tensile strength yield T6 were improved, while uniform elongation are almost not T4P state both improved. obtained results help further shorten production cycle slabs improve mechanical properties.