The research object is A356 aluminum alloy sleeve, whose appearance is shown in Figure 1. The overall shape of the sleeve is cylindrical, with raised parts in the middle and sides, and the structure is relatively complex. The overall dimension of the casting is 366 mm × 295mm × 226 mm, average wall thickness 12 mm, maximum wall thickness 36 mm, mass 11.85 kg.

The casting adopts metal mold low-pressure casting, and the mold uses hot working mold steel H13. The sand core is a composite sand core made of coated sand material, and the low-pressure furnace uses a crucible furnace. The structure of the low-pressure casting gating system for aluminum alloy sleeves is shown in Figure 2. In the actual production trial production process, this type of sleeve is prone to defects in the outer thick parts and wall surfaces, so it is necessary to optimize the process parameters to improve the quality and yield of the sleeve.