Microstructure and hardness of Al2O3 nanoparticle reinforced Al-Mg composites fabricated by reactive wetting and stir mixing

► Solidification synthesis of Al-Cu-Mg alloy - Al2O3 nanocomposite by reactive wetting and mixing. ► Composites produced via reactive wetting and stir mixing exhibit improved hardness. ► Microstructure and strengthening depend on re-agglomeration level after reaction completion.