Low Pressure Die Casting

How Does Low-Pressure Die Casting Work?

01 Design Preparation

Low-Pressure Die Casting (LPDC) design fundamentals are similar to other casting processes: Maintaining uniform wall thickness, avoiding sharp corners and thick sections, apply proper draft angles and select suitable materials. What differs is that molten metal is pushed upward into the mold, which requires bottom gating. This must be carefully reflected in the CAD design to ensure smooth metal flow and proper venting.

02 The Process

The die is mounted on a sealed furnace or crucible containing molten metal, typically aluminum or magnesium alloys. A ceramic riser tube connects the molten material to the die cavity. Compressed gas forces the molten metal upward through the riser tube and into the mold cavity in a smooth, controlled flow. Pressure is maintained during solidification to compensate for shrinkage and produce dense, low-porosity castings.

03 Post-Production

Gating and riser connections are removed after casting. Heat treatment is often applied to enhance the part’s strength and ductility. Machining may be used to refine critical surfaces, drill holes or cut threads. Surface finishing options include anodizing, painting and powder coating to improve corrosion resistance and appearance.

Is Low-Pressure Die Casting a Fit for Your Needs?

Advantages

Improved Metal Flow and Porosity

LPDC ensures even metal flow, which reduces turbulence and minimizes trapped air. The result: few porosities and stronger, more reliable castings compared to high-pressure die casting.
Better Mechanical Properties

Parts produced under low pressure generally have higher density and fewer internal defects. This improves tensile strength, fatigue resistance and overall durability compared to high-pressure die casting.
Dimensional Accuracy

The controlled flow enables precise filling of intricate mold features. This reduces the need for extensive machining or post-processing.
Reduced Material Waste

Overflow is minimal because the metal is pushed gradually into the mold. This conserves expensive alloys and keeps scrap rates low.
Thin Walls & Complex Shapes

LPDC excels at producing parts with thin sections that are difficult to achieve through gravity casting. Complex geometries can be formed without compromising structural integrity.

Disadvantages

High Initial Costs

LPDC requires specialized furnaces, pumps and molds. The initial investment is significantly higher compared to gravity casting or other simpler methods.
Slower Production Rate

Filling the mold under low pressure is slower than high-pressure die casting. This can limit production speed, especially for large part orders.
Complex Process Control

Operators must precisely control temperature, pressure and timing. Even small deviations can lead to defects such as cold shuts or incomplete filling.

What Industries Are The Best Fit For Low-Pressure Die Casting?

Low-pressure die casting is a match for industries that need components that are strong, light and precise.

Aerospace

Aerospace manufacturers use LPDC for components such as housings, brackets and engine parts. It ensures superior metallurgical integrity and precision, which are essential for safety-critical and high-temperature aerospace and defense applications.

Automotive

LPDC is widely used to produce lightweight aluminum wheels, suspension components and structural parts. It delivers a high strength-to-weight ratio and excellent dimensional consistency needed for vehicle performance and fuel efficiency.

Industrial Machinery

LPDC components are found in pumps, compressors and heavy-duty machinery housings. It enables durable, defect-free parts that can withstand continuous mechanical and thermal stress.

Energy

The energy industry employs LPDC to create parts for wind turbines, power generation equipment and electric motor housings. Its ability to produce large, complex aluminum components with minimal porosity maximizes efficiency and reliability.

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