
How does the low pressure die casting process work?
Low pressure die casting is another method of metal casting, used predominantly for creating aluminium parts. Unlike the high pressure and gravity die casting methods offered by NSD, this process is generally considered to be less precise, especially for highly detailed or thin-walled parts.
In low pressure die casting, the die is filled with metal from a pressurised furnace, with pressures typically around 0.7 bar.
The holding furnace is positioned in the lower part of the vertical die casting machine, with the molten metal injected upwards directly into the bottom of the mould.
The pressure holds the metal in the die until it solidifies.
Process Description
Controlled Pressure Application. In low pressure die casting, molten metal is pushed into the mold using a low, controlled pressure. This is in contrast to the high-pressure injection used in high pressure die casting.
Die Design. The dies used are similar to those in gravity and high pressure die casting but are oriented differently to accommodate the pressure application from below.
Cooling and Solidification. After the metal is injected into the die, it solidifies under pressure before being released.
Although suitable for medium complexity parts, low pressure die casting doesn't quite match the precision and ability to fill intricate molds that high pressure die casting offers. Also, compared to gravity die casting, it may produce parts with slightly less dimensional stability, particularly for very detailed designs.
Comparative Disadvantages
Advantages of the low pressure die casting process
One of the main advantages of this process is the precise control of die cavity filling.
Molten metal flows quickly and smoothly through the feeding conduits, reducing oxide formation and preventing porosity.
Limited Material Options. Unlike the versatile material options available in high pressure and gravity die casting, low pressure die casting is generally limited to aluminium and its alloys.
Reduced Complexity in Parts. While capable of producing good quality parts, low pressure die casting is not as effective as high pressure die casting in creating highly complex or thin-walled structures.
Slower Production Speed. The cycle times for low pressure die casting are generally longer than high pressure die casting, making it less efficient for large-scale production.
Lesser Dimensional Accuracy. Compared to high pressure die casting, this method may not achieve the same level of dimensional accuracy and stability, which is crucial for parts requiring tight tolerances.
Applications and Limitations
This process was created for the production of axially symmetrical parts such as car wheels.
Automotive and Aerospace. Low pressure die casting is used for components that do not require the intricate geometries or extreme precision that high pressure die casting provides.
Cost Considerations. While the tooling costs might be lower than high pressure die casting, the overall production speed and efficiency are also lower, making it less economical for large volume production.
However, by employing sand cores within the die, it is also well suited to producing parts with hollow sections and complex geometries.
Discover our low pressure die casting solutions here:
- LPG Series:
Low pressure machine range for the production of complex automotive castings. -
Turnkey Fully Automated Cells:
Flexible, fully automated work cells for light alloy casting production. We engineer automated work cells for three die casting processes: high pressure die casting, gravity die casting and low pressure die casting.
While low pressure die casting is a viable method for certain applications (particularly where moderate complexity and volume are involved), it does not offer the same level of precision, efficiency, and versatility as the high pressure and gravity die casting methods provided by NSD. We choose to focus on high pressure and gravity die casting as they better serve the needs of OEMs seeking high-quality, complex parts with faster production times and higher precision.
NSD VINA CO., LTD - Industrial Solutions
Add: 03, Violet 1, Vinhomes Gardenia, Nam Tu Liem, Hanoi, Vietnam
Tel: 024-6688-2448
Email: info@nsdvn.com