Investigating the micro-structures of A356 semi-solids based on electromagnetic stirring currents and crucible materials

In this study, the characteristics of microstructures in a liquid state were investigated; these microstructures were produced via electromagnetic stirring using semisolid forming methods. The spherical structures were studied under the application of variable currents using a large electromagnet in order to stir molten metal with a maximum weight of 5–20 kg, which is a range that is commonly used in industries. Moreover, the changes in the microstructures of metal slurries were investigated based on the type of crucible used. Additionally, the size and roundness of the primary α-Al particles were analyzed according to the variable input current. Crucibles composed of ceramics, SUS304, and HK40 were used for the experiment to measure electromagnetic forces. For the HK40 crucible, the average size of the primary α-Al particles was 67.8 µm and their roundness was 2.4. When a current of 120 A was applied, these values were 21.40 µm and 2.3. Thus, it could be concluded that the stirring was well-executed under an input current of 120 A.