Working Principle of the Low Pressure Casting Machine

2025,09,12

The core of the Low Pressure Casting Machine is to use low-pressure gas to drive molten metal, combining controlled filling with pressure feeding to achieve casting formation. It primarily targets non-ferrous metal castings such as aluminum alloys and magnesium alloys (e.g., automotive wheels and aviation parts), ensuring both quality and efficiency.

Its operation consists of four core steps, each closely linked to ensure casting quality:

Pressure and Temperature Preparation: A sealed crucible is filled with molten metal and connected to the mold gate. Dry compressed/inert gas (to prevent oxidation) is introduced, and the pressure is slowly increased to 0.02-0.15 MPa while temperature control is maintained to maintain the molten metal's fluidity.

Smooth Filling: Gas pressure propels the molten metal up the pipe, slowly filling the mold cavity. Precise pressure control is employed – too high a speed can lead to air bubbles, while too low a speed can block the runner. Low pressure ensures that even complex cavities are filled.

Pressure-holding and shrinkage-feeding: After the mold cavity is filled with liquid, the pressure is maintained constant (holding pressure for tens of seconds to several minutes). As the molten metal solidifies, the remaining liquid in the crucible is pressurized to fill the shrinkage voids, preventing shrinkage cavities and porosity and improving the density of the casting.

Pressure-relieving and part removal: After the casting solidifies, the pressure is released, and the residual liquid in the pipe flows back into the crucible (recoverable). After the mold is opened, the ejector mechanism removes the part, completing the cycle.

Modern models are equipped with intelligent systems that monitor parameters such as pressure and temperature in real time and automatically adjust them. This improves casting precision while reducing operational complexity. High molten metal utilization and low pollution have made them a mainstream casting technology.

Author:

Ms. Hu

E-mail:

dgliheng168@163.com

Phone/WhatsApp:

+86 13509684273