300 mm×1000 mm Al-6Mg-0.4Mn-0.4(Sc-Zr) ingot was produced by semi-continuous casting method. The effect of homogenization annealing on the hardness, electrical conductivity and microstructure of the as-cast alloy was studied. The results show that during homogenization annealing treatment, homogenization below 350 ℃, hardness of the alloy increases with the increasing of homogenization temperature and time, homogenization above 350 ℃, the hardness and hardness peak of the alloy decreases with the increasing...