Research on Microstructure of the Al-20%Mn Alloy Prepared by Mixed Solid-liquid Casting

Common casting high alloyed Al-Mn alloy with compositions about 20% can not be used as structural materials due to coarse microstructures which lead to lower mechanical properties. In this paper, a novel mixed semi-solid casting technology was applied to prepare Al-20%Mn alloy. The formation mechanisms of minicrystal structure during mixed solid-liquid casting process were also discussed. The experimental results show that the grain can be obviously refined via this new developed technology, the average grain size of the as-prepared samples was less 10μm with spherical and near-spherical shape. The microstructure is better than that of the alloys prepared by common casting or semi-solid casting without adding powder.