The integral microstructure of semisolid A356 alloy slurry with larger capacity cast by serpentine channel was studied and the influence of cooling ability of serpentine channel on the microstructure was investigated. The results indicate that ideal slurry with larger capacity can be prepared through serpentine channel with good cooling ability. When the serpentine channel was continuously cooled, both the longitudinal and the radial microstructure of the slurry was composed of granular primary phase and the integral microstructure uniformity of the slurry was good. However, uncooled serpentine channel can only produce larger slurry with fine grains in positions adjacent to its centre and with a large number of dendrites in positions close to its edge, thus, the radial microstructure of larger slurry is nonuniform. The pouring temperature is set up to 680 °C and the solid shell inside the channel can be avoided at this pouring temperature.
