AlSi9Mg aluminum alloy semi-solid slurry preparation by intermediate frequency electromagnetic oscillation process

A novel method is developed herein to simplify the process of semi-solid forming. The process working principle is similar to that of intermediate frequency heating. In this preparation process, the melting process and stirring process are combined. Nucleation and dendrite growth of the metallic material are affected by the intermediate frequency electromagnetic stirring and forced convection. The AlSi9Mg aluminum alloy is investigated in intermediate frequency electromagnetic oscillation process (IFEOP). Experiments and simulations are carried out to study the effect of process parameters. After about 10 periods of time, the average size of the semi-solid slurry grains was 28 μm, the dimensionless shape factor was 0.87 and the porosity was 0.15%. Grains turn to spherical crystal when the semi-solid material was reheated to 565 °C for 25 min or to 575 °C for 10 min. The number of periods, holding time and holding temperature were observed to have significant influences on properties of semi-solid material.