Effect of holding temperature on semisolid microstructure of Mg2Si/Al composite

A semisolid microstructure of Mg2Si/Al composite is successfully achieved by isothermal heat treatment process, and the effects of holding temperature on semisolid microstructure of the composites are investigated. The result shows that, at the low heat treatment temperature, the morphology of primary Mg2Si particles are identified as irregular shape and alpha-Al grains exhibit elliptic and/or rosette type, and their sizes are non-uniform from 35 to 130 mum and 41 to 191 mum, respectively. With the increasing of treatment temperature, the morphologies of primary Mg2Si and alpha-Al grains change to spherical type, and their sizes decrease and become relatively uniform.