Gravity Die Casting vs. Low Pressure Die Casting: How to Choose the Right Die Casting Machine for Your Production Needs?

2025,06,28

1. Process principle and technical characteristics

1. Gravity casting: The mold filling is completed by relying on the deadweight of the molten metal, and the flow rate depends on the pouring height and metal density. The advantage is that the mold pressure is uniform and a smooth surface can be formed; the limitation is that it is difficult to achieve complete filling of complex cavities.

2. Low pressure casting: A sealing system is used to control the filling speed. The core advantage is that it can accurately replicate mold details, especially suitable for thin-walled parts and hollow structures; but the need for a matching pressure control system increases the complexity of the equipment

2. Scope of application and molding effect

1. Gravity casting: Suitable for large castings over 20kg and simple geometric bodies, typical applications include building components and mechanical bases. The molded parts have low residual stress characteristics, but they need to be combined with manual filling to deal with local defects.

2. Low-pressure casting: Specializes in the field of precision parts, and automobile wheels and aviation turbine housings are representative products. Cold shut defects can be eliminated through controllable pressure, but the mold design requires higher precision.

3. Economic analysis and process selection

1. Gravity casting: Equipment investment is only 30%-50% of that of the low-pressure system, and the energy consumption cost of a single piece is reduced by more than 40%, but the yield is limited by the complexity of the mold.

2. Low-pressure casting: Although the equipment maintenance cost is 2-3 times higher, the comprehensive cost of complex parts is reduced by 15%-20%, which is especially suitable for high value-added products.

Gravity casting and low-pressure casting are both suitable for materials such as aluminum alloys and magnesium alloys. However, gravity casting can also be used for cast iron, copper alloys, etc., and its application range is relatively wider. If you are producing cast iron parts, you can generally only choose gravity casting machinery.

Low-pressure casting fills and solidifies under pressure, and the casting has less shrinkage, high density, and few internal pores. It is suitable for the production of parts with high internal quality requirements and that need to withstand high pressure or dynamic loads, such as automobile engine cylinders.

Gravity casting equipment has a simple structure, low investment cost, and relatively low mold cost, especially sand casting. However, gravity casting has low production efficiency and may have high labor costs, which is suitable for small batch production. Low-pressure casting equipment is complex, including crucibles, air pressure control systems, etc., with high investment costs and mold costs, but the material utilization rate is high, and the unit cost will be reduced during mass production, which is suitable for mass production.

To select a Casting Machine that suits production needs, it is necessary to comprehensively consider factors such as casting characteristics, production efficiency, and cost.

Author:

Ms. Hu

E-mail:

dgliheng168@163.com

Phone/WhatsApp:

+86 13509684273