Effect of compound process on semi-solid slurry of A356 aluminum alloys

The semi-solid slurry of A356 aluminum alloy was prepared by a method of low superheat pouring and weak traveling-wave electromagnetic stirring and the effects of pouring temperature, stirring power and stirring time on the semi-solid slurry were investigated. The results show that the nucleation sites for primary α-Al quickly spread throughout the whole melt region and the number of nuclei can be increased at the same time. So the grain density is high enough in the early stage of solidification and the spherical primary α-Al grains are formed in the end. When a spherical semi-solid A356 aluminum alloy slurry is manufactured by this method, the proper pouring temperature, stirring power and stirring time should be 630°C, 1.2 kW and about 6s respectively. On the condition of weak traveling-wave electromagnetic stirring, the pouring temperature can be suitably raised and the same ideal spherical microstructure, which is usually gotten only from a lower pouring temperature without stirring, can also be obtained. Therefore the pouring operation is simple and convenient.