What is the difference between low pressure casting and high pressure casting?

Low pressure casting and high pressure casting are two commonly used casting processes. They have some differences in casting process, process parameters and product performance.

1. Casting process

Low Pressure Casting: Low pressure casting is a casting method in which molten metal is poured into a mold. Its characteristic is to use lower pressure (usually .1-.3MPa) to inject molten metal into the mold from the bottom or side to fill the mold cavity.

High-pressure casting: High-pressure casting is a casting method that uses high pressure (usually between 100-200MPa) to inject molten metal into a mold. It is characterized in that molten metal is propelled by high pressure in a closed casting chamber to fill the mold cavity.

2. Process parameters

Low Pressure Casting: The pressure used in the low pressure casting process is low, the operation is relatively simple, and it is suitable for larger castings. At the same time, low-pressure casting can achieve better filling effect through pressure control and reduce the occurrence of defects.

High-pressure casting: The pressure required for high-pressure casting is higher, and the requirements for equipment and molds are also higher. It is suitable for the production of precision castings and can obtain higher dimensional accuracy and surface quality.

3. Product performance

Low-pressure casting: Low-pressure casting can usually obtain better crystal structure and mechanical properties of castings, and avoid or reduce defects. During the casting process, the metal flow rate is slower, which is beneficial to reduce the generation of defects such as pores and inclusions.

High-pressure casting: High-pressure casting can produce denser castings because high pressure helps to remove gases and impurities. At the same time, high-pressure casting can also obtain high mechanical properties and fatigue strength, which is suitable for the manufacture of parts subject to high load and high pressure.

In short, there are differences between low pressure casting and high pressure casting in terms of pressure, process parameters and product performance. Selecting a suitable casting process needs to take into account specific product requirements and production conditions.