Abstract
Reheating and isothermal holding was carried out using strained bulk, briquet and chip in order to get fine solid particle. Furthermore, semi-solid stirring was conducted employing chips, with fine solid particles during isothermal holding. Magnesium solid solution (α-phase) in each raw material recrystallizes on reheating and then melting occurs at interface between α-phase and eutectic compound, and recrystallized grain boundary below holding temperature. At isothermal holding temperature, solid particles break up nearly perfectly, and are finer spherical particles than those of commercial bulk sample. The spherical solid particle coarsens in proportion to cube root of holding time. From analyses of distribution form of solid particle diameter, it is clear that contribution of coalescence to the particle growth decreases and that of Ostwald ripening increases with the lapse of time. When chip sample is stirred, solid particle size is a half of that of bulk sample and the volume fraction of liquid phase increases. Moreover, growth of the solid particle is little even though stirring temperature raises. Amount of liquid phase increases and the fluidity of slurry improves with the increase of holding temperature.
