Pure aluminum die casting refers to a metal forming process that uses high-purity aluminum (typically with an aluminum content of ≥99.5% or 99.7% and above) as raw material to produce parts through the die casting process (high-pressure casting).
Die casting is a process in which molten metal is rapidly injected into a metal mold (die) under high pressure, then cooled and solidified to form the casting. The main difference between pure aluminum die casting and common aluminum alloy die casting lies in the raw material:
- Pure Aluminum: Extremely high aluminum content, with almost no other elements added or only minimal amounts.
- Aluminum Alloy: Other elements such as silicon (Si), copper (Cu), magnesium (Mg), etc., are added to improve performance (common grades include ADC12, A380, etc.).
Characteristics of Pure Aluminum Die Casting (Comparison with Aluminum Alloy Die Casting)
| Item | Pure Aluminum Die Casting | Aluminum Alloy Die Casting (Common) |
|---|---|---|
| Aluminum Content | ≥99.5% (often ≥99.7%) | Typically 85–95% |
| Fluidity | Poor (higher melting point, higher viscosity) | Good (improved by elements such as silicon) |
| Melting/Pouring Temperature | Higher (pouring temperature usually 680–790°C) | Lower (easier to operate) |
| Strength/Hardness | Lower (pure aluminum is relatively soft) | Significantly higher |
| Thermal/Electrical Conductivity | Excellent | Good (slightly lower than pure aluminum) |
| Oxidation/Corrosion Resistance | Excellent | Good |
| Shrinkage Rate | Larger | Smaller |
| Applications | Parts requiring high thermal/electrical conductivity, anodizing, or high appearance standards | Structural parts requiring high strength |
Advantages and Disadvantages
Advantages:
- Excellent thermal and electrical conductivity (ideal for heat sinks, electronic components, motor rotors, etc.).
- Good oxidation resistance and corrosion resistance.
- Excellent anodizing performance (surface treatment), with uniform color and good gloss.
- Lightweight with high recycling value.
Disadvantages:
- Poor fluidity, prone to defects (such as porosity and shrinkage), and higher process requirements (mold, temperature, pressure, etc., need careful adjustment).
- Lower mechanical strength, not suitable for structural parts under high stress.
- Usually higher production cost (more expensive raw material and more difficult process).
Common Applications
- Motor/generator rotors (pure aluminum rotor die casting).
- High-end heat sinks and LED lighting heat sinks.
- Electronic enclosures or components requiring good surface finish and thermal conductivity.
- Certain special parts that require high purity or specific electrical conductivity.