AlSi7 Aluminium
UNS A13570 (EN AC-AlSi7Mg0.6, A357, AMS 4289)
- Lightweight alloy with excellent corrosion resistance
- High strength-to-weight ratio and good fatigue performance
- High thermal conductivity
- Heat-treatable to T6 condition for enhanced properties
- Excellent weldability and suitability for additive manufacturing
AlSi7 Aluminium powder is a beryllium-free aluminum-silicon-magnesium alloy derived from A357, optimized for additive manufacturing. It offers a combination of low density, good corrosion resistance, and high mechanical performance, making it ideal for aerospace, automotive, and defense applications. Its ability to undergo T6 heat treatment further enhances strength and fatigue resistance.
🏭 Industry Sectors
- Aerospace: Structural components, heat exchangers
- Automotive: Lightweight performance parts
- Defense: High-strength, corrosion-resistant components
- Industrial: Heat transfer and dynamic load-bearing parts
Composition
| Element | Weight % |
|---|---|
| Al | Bal. |
| Si | 6.5 – 7.5 |
| Mg | 0.4 – 0.8 |
| Fe | ≤ 0.2 |
| Mn | ≤ 0.1 |
| Cu | ≤ 0.2 |
| Zn | ≤ 0.1 |
| Ti | ≤ 0.2 |
| B | ≤ 0.002 |
| Others | ≤ 0.15 total |
Alloy Powder Sizes
| Size Distribution | Typical Uses |
|---|---|
| 10 to 90 µm | Binder jetting |
| 15 to 60 µm | Laser – Powder Bed Fusion (L-PBF) |
| 15 to 106 µm | Electron beam – Powder Bed Fusion (E-PBF) |
| 45 to 180 µm | Direct Energy Deposition (DED) |
Heat Treatment
- Solution Treatment: ~540 °C for 30 min, water quench
- Aging (T6): 160–170 °C for 6–8 hours
- HIP (optional): Improves density and fatigue properties
Note: Shortened solution treatments are often used for AM parts to preserve fine microstructure.
Key Materials Properties
| Property Type | Property | Value |
|---|---|---|
| Mechanical | Yield Strength | 180 – 260 MPa |
| Mechanical | Ultimate Tensile Strength | 250 – 350 MPa |
| Mechanical | Elongation to break | 8 – 12% |
| Mechanical | Young’s Modulus | 72 GPa |
| Mechanical | High Cycle Fatigue limit | |
| Mechanical | Hardness | 120 HB |
| Thermal | Conductivity | 130-160 W/m.K |
| Thermal | Expansion Coefficient | ~23 ×10⁻⁶ /°C |
| Electrical | Resistivity | 3-5 μΩ.cm |
| Physical | Corrosion Resistance | Good |
Corrosion Resistance
Excellent corrosion resistance in atmospheric and marine environments due to the protective oxide layer.
Heat Resistance
Maintains mechanical integrity up to ~200 °C; above this, strength decreases significantly.
Welding
Excellent weldability with standard processes; autogenous weldability makes it suitable for LPBF.
Machining
Good machinability; use sharp tools and adequate lubrication to avoid built-up edge.