What is Low-Pressure Casting ?Low-pressure casting (Low-Pressure Casting, abbreviated as LPC) is a metal casting process that primarily uses low pressure (typically 0.1-1.0 bar, or about 10-100 psi) to slowly inject molten metal from the bottom of the mold into the mold cavity, achieving the formation of the casting. Unlike high-pressure casting (such as die casting), it uses gas pressure (such as nitrogen or air) to push the molten metal upward to fill the mold, avoiding pores and inclusion defects caused by high-speed impact, thereby obtaining a denser casting structure. This process is particularly suitable for non-ferrous alloys, such as lightweight metals like aluminum alloys and magnesium alloys.Application ScenariosLow-pressure casting is widely used in the production of castings requiring high strength, high density, and complex shapes. The main scenarios include:
- Automotive Manufacturing: Used to produce key structural components such as engine cylinder blocks, cylinder heads, wheel hubs, transmission housings, and pump housings. These parts require good mechanical properties and surface finish to withstand high-temperature and high-pressure environments.
- Electric Motors and Appliance Industry: Such as aluminum alloy motor housings and radiators, leveraging their excellent thermal conductivity and lightweight characteristics.
- Aerospace and Motorcycle Fields: Production of lightweight alloy components, such as aircraft structural parts or motorcycle frames, emphasizing weight reduction and fatigue resistance.
- Others: Medical equipment, electronic radiators, and high-end consumer products (such as bicycle components), suitable for batch production scenarios that prioritize quality over extremely high speed.
Application ScopeThe scope of low-pressure casting mainly focuses on non-ferrous metal casting and is suitable for parts with complex alloy compositions, uneven wall thicknesses, or requiring high surface quality. Its advantages include:
- Material Scope: Aluminum alloys (most common), magnesium alloys, copper alloys, etc.; not suitable for iron-based alloys (such as steel) because they are prone to oxidation at high temperatures.
- Part Size and Complexity: Suitable for medium to large complex castings (weights from a few hundred grams to tens of kilograms), with wall thicknesses up to 2-5 mm, supporting thin-wall designs.
- Production Efficiency: Suitable for medium-batch production (10-50 pieces per hour), with high casting yield rates (>95%), but slower than high-pressure casting.
- Limitations: High initial equipment investment, suitable for industries with high precision requirements; not suitable for ultra-thin walls or extremely high-volume scenarios.
Overall, low-pressure casting balances quality and cost, making it a key technology in the lightweighting trend of modern manufacturing.
Specific Application Cases of Low-Pressure CastingBased on your request, I have further queried specific cases of low-pressure casting in actual industrial applications. These cases are mainly concentrated in the fields of automobiles, electric vehicles, aerospace, and power equipment, demonstrating the advantages of this process in producing high-precision, lightweight components. Below, I list some typical cases, including process details and benefits:1. Automotive Wheel Hub Casting
- Case Description: Using A356.2 aluminum alloy for low-pressure casting to produce automotive aluminum alloy wheel hubs. Through simulation analysis, shrinkage defects are optimized to ensure the mechanical strength and surface quality of the wheel hubs. This process accounts for the highest proportion in wheel hub manufacturing and is commonly used in mid-to-high-end sedans and SUVs.
- Benefits: Weight reduction of 15-20%, improved fatigue resistance, and a yield rate exceeding 98%.
- Applicable Scenarios: Large-scale automotive production, such as wheel hub components for Volkswagen or General Motors.
2. Electric Vehicle Water-Cooled Housing
- Case Description: For the continuous production of aluminum alloy water-cooled housings for electric vehicles using low-pressure casting, an intelligent information system is adopted to track changes in spiral sand cores and control casting defects. The process includes real-time monitoring after mold closing to ensure uniform housing wall thickness (2-5 mm).
- Benefits: Reduces scrap rates caused by sand core damage, improves traceability efficiency, and is suitable for new energy vehicle battery cooling systems.
- Applicable Scenarios: Thermal management systems for electric vehicles from brands like BYD or Tesla.
3. Aluminum Alloy Motor Housing
- Case Description: Taking a 140 kW motor housing as an example, a low-pressure sand casting process design is used, with MAGMA simulation to optimize the pouring system and cooling design, avoiding pores and inclusions. Suitable for medium to large motor housings.
- Benefits: High casting density (>99%), good thermal conductivity, and a 20% reduction in production cycle time.
- Applicable Scenarios: Industrial motors and new energy vehicle drive motors, such as products from Siemens or ABB.
4. Automotive Chassis Safety Components
- Case Description: Low-pressure casting process for high-strength automotive chassis safety aluminum alloy castings (such as brackets or guards), including alloy melt preparation, low-pressure injection, and aging treatment. Pressure is controlled at 0.3-0.6 bar to ensure high strength (>300 MPa).
- Benefits: Enhances collision safety, 30% lighter than steel, and strong corrosion resistance.
- Applicable Scenarios: Safety-critical components, such as BMW or Mercedes-Benz chassis systems.
5. Motor Aluminum Alloy Rotor
- Case Description: Low-pressure casting for double straight-slot double helical-slot aluminum alloy rotors, used in ultra-high-efficiency motors (IE4/IE5 level). The process shifts from traditional gravity casting to low-pressure to achieve filling of complex slot shapes.
- Benefits: Rotor efficiency improved by 5-10%, suitable for high-speed motors, and reduces energy loss.
- Applicable Scenarios: High-efficiency motor production, such as wind power generation or power tools.
6. Aerospace Engine Bracket
- Case Description: Using low-pressure casting mold reverse deformation design to produce engine brackets, ensuring deformation control within ±0.2 mm after heat treatment. Aluminum alloy is used, combined with finite element analysis to optimize the mold.
- Benefits: Eliminates 80% of post-correction processes, reduces weight by 15%, and improves structural integrity.
- Applicable Scenarios: Commercial aircraft or drone engine components, such as suppliers for Boeing or Airbus.
7. Power Equipment High-Voltage Housing
- Case Description: Low-pressure casting for high-voltage housings, focusing on filling control in areas with uneven wall thickness. The process includes ceramic transfer tubes and nitrogen pressurization.
- Benefits: Stable insulation performance, suitable for high-voltage environments, and higher production efficiency than sand casting.
- Applicable Scenarios: Transformer or generator housings, such as Siemens power products.
These cases highlight the role of low-pressure casting in lightweighting and precision manufacturing.