A356 has been one of the most demanded, used, and preferred aluminum die casting alloys. Its excellent load-carrying capacity makes the alloy a preferred material in aircraft applications. And the material’s properties, composition, advantages, and application have been highlighted below.
Aluminum A356 Characteristics
A356 is a Al 3xxx series alloy as per the Aluminum Association (AA) system. Its alpha-numeric ID is A13560 in the UNS standard. The most noteworthy features of this material include –
- Heat-treated for strength
- Good casting & machining
- Outstanding weldability
- Superb mechanical stability
- Low chemical impurities
- Reduced/minimal ductility
- High corrosion resistance
Aluminum A356 Chemical Composition
| Content | Value |
| Aluminum (Al) | Balance |
| Silicon (Si) | 6.50% – 7.50% |
| Magnesium (Mg) | 0.25% – 0.45% |
| Copper (Cu) | 0.20% (max) |
| Titanium (Ti) | 0.20% (max) |
| Iron (Fe) | 0.20% (max) |
| Manganese (Mn) | 0.10% (max) |
| Zinc (Zn) | 0.10% (max) |
| Others | 0.15% (max) |
Aluminum A356 Properties
The general properties of A356 can be outlined as follows –
| Properties | Value |
| Density | 2.6 g/cm3 |
| Melting Temperature | 570°C – 610°C |
| Elastic Modulus | 70 GPa |
| Shear Modulus | 26 GPa |
| Thermal Expansion | 21 µm/m-K |
| Thermal Conductivity | 150 W/m-K |
The properties can vary as different alloys are available under the A356 designation itself. A356.0 indicates the casting alloy, whereas A356.1 and A356.2 denote ingots. However, die-casting aluminum alloy refers to A356.0 unless specified.
Meanwhile, there are 5 (five) variations within the A356.0 itself based on tempers. They are –
- 0-F
- 0-T51
- 0-T6
- 0-T61
- 0-T71
A356.0-T51, A356.0-T6, and A356.0-T71 are the most widely used variations. Their comparative mechanical properties are tabulated below –
| Properties | A356.0-T71 | A356.0-T6 | A356.0-T51 |
| Yield Strength | 140 GPa | 200 GPa | 120 GPa |
| Ultimate Tensile Strength | 210 GPa | 270 GPa | 180 GPa |
| Fatigue Strength | 50 MPa | 90 MPa | 53 MPa |
| Maximum Elongation | 3.0% | 6.0% | 3.0% |
T5 refers to quenching or solution treatment with incomplete artificial aging, whereas T6 utilizes full artificial aging. However, T7 features stabilization tempering for the solution treatment or quenching.
Applications of Aluminum A356 Alloy
Sufficient pressure resistance, excellent air tightness, and no hot-cracking tendency make A356 popular in many leading industries. Some of the sectors to readily use this material include –
- Different castings
- Aircraft components
- Automobile transmissions
- Machinery tools
- High-speed blowers
- Pump components
- Nuclear energy installation
- Permanent molding
- High-strength frames
Any task involving high-strength yet lightweight and mechanically superior tools can utilize A356. The heat treatment status means a lot to achieve the desired A356.0 properties.
T5 induces strength and plasticity but compromises the corrosion resistance. T6 integrates the highest strength for reduced plasticity and corrosion resistance. And T7 incorporates a more balanced mechanical performance, especially for castings.
A356 vs 6061
A356 can effectively replace Aluminum 6061 alloy in many applications. Their respective differences in mechanical properties are –
| Properties | A356.0-T6 | 6061-T6 |
| Density | 2.6 g/cm3 | 2.7 g/cm3 |
| Elongation at Break | 6% | 10% |
| Yield Strength | 200 GPa | 270 GPa |
| Tensile Strength | 270 GPa | 310 GPa |
| Fatigue Strength | 90 MPa | 96 MPa |
| Melting Point | 570°C | 580°C |
| Thermal Expansion | 150 W/m-K | 170 W/m-K |
| Thermal Conductivity | 24 µm/m-K | 21 µm/m-K |
The comparison clearly denotes that 6061 is superior to A356. Still, industries often choose A356 for its unmatched versatility and adaptability. Also, A356 possesses over 90% of 6061’s mechanical properties.
Sunrise Metal is a leading Chinese aluminum die casting service provider with years of experience. We not only offer a wide range of choices but also deliver expert suggestions. Contact us anytime to discuss your project.