Material Name : GD-ALSi12Cu
Material Identification & Standards
GD-ALSi12Cu is classified as an Al-Si-Cu die casting alloy. Equivalent designations include:
- JIS (Japan): ADC12
- AA (USA): A383
- BS (UK): LM24 (BS 1490)
- DIN (Germany): GD‑AlSi12Cu (DIN 1725)
- ISO (International): Al‑Si12Cu (ISO 3522)
- Common Use Type: Al-Si-Cu die casting alloy
- EN (Europe): EN AC‑44300 (EN 1706)
BS 1490 LM24 is a broad designation covering multiple aluminum-silicon-copper alloys. Both GD-ALSi8Cu3Fe and GD-ALSi12Cu fall within the LM24 compositional range, hence they are mapped to this grade.
EN 1706 is a standard designation, officially titled:
EN 1706: Aluminium and aluminium alloys — Castings — Chemical composition and mechanical properties.
It is a European Standard (EN) that specifies the chemical composition and mechanical properties of cast aluminum alloys.
Therefore, all European cast aluminum alloys, such as EN AC‑44300, EN AC‑44100, EN AC‑43000, etc., are defined and governed under the framework of EN 1706.
Chemical Composition
- Silicon (Si): 10.0 – 13.0%
- Copper (Cu): 1.0 – 3.0%
- Magnesium (Mg): ≤ 0.5%
- Iron (Fe): ≤ 1.3%
- Manganese (Mn): ≤ 0.5%
- Zinc (Zn): ≤ 1.0%
- Nickel (Ni): ≤ 0.5%
- Others (Sn, Pb, Ti, etc.): ≤ 0.5%
- Aluminum (Al): Balance
Mechanical & Physical Properties
| Property | Typical Value Range |
| Tensile Strength | ~280 – 330 MPa |
| Yield Strength | ~160 – 210 MPa |
| Elongation | ~1.5 – 4 % |
| Brinell Hardness | ~85 – 100 HB |
| Density | ~2.65 – 2.7 g/cm³ |
| Melting Temperature | ~570 – 615 °C |
Thermal & Electrical Properties
| Property | Typical Value Range |
| Thermal Conductivity | ~90 – 110 W/m·K |
| Electrical Conductivity | ~15 – 25 % IACS (~8.8–14.7 MS/m) |
| Thermal Expansion Coefficient | ~20 – 23 µm/m·K |
Pros & Cons Summary
| Feature | Pros | Cons |
| Strength & Hardness | Higher strength than pure Al-Si alloys due to Cu addition | Moderate ductility (~1.5–4%) |
| Castability | Good castability and fluidity | Copper may reduce corrosion resistance slightly |
| Corrosion Resistance | Reasonable corrosion resistance in general environments | Not ideal for highly corrosive marine conditions without coatings |
| Machinability | Good machinability and surface finish | Requires appropriate cutting parameters |
Castability & Corrosion Resistance
GD-ALSi12Cu exhibits excellent fluidity and filling ability, making it suitable for complex die-casting components. The copper content increases mechanical strength but may slightly reduce corrosion resistance compared to Cu-free Al-Si alloys. Proper protective coatings or treatments are recommended for harsh environmental exposure.
Key Characteristics
- Balanced silicon and copper content for strength and castability
- Improved wear resistance due to copper alloying
- Suitable for automotive engine parts, housings, and structural applications
- Moderate elongation and hardness suitable for high-stress components
Common Applications
- Automotive components: engine covers, transmission housings, brackets
- Electrical housings and enclosures
- Mechanical parts requiring high strength and wear resistance
Conclusion & Recommendation
GD-ALSi12Cu is an ideal alloy for die-cast components requiring a balance of strength, wear resistance, and good castability. It suits automotive and industrial applications where improved mechanical performance over standard Al-Si alloys is necessary, with attention to corrosion protection.