Aluminium alloys are widely used across multiple industries due to their excellent strength-to-weight ratio, corrosion resistance, and adaptability. Among these, 5086 aluminium coil stands out as a high-strength, marine-grade alloy known for its superior mechanical properties, especially its strength, weldability, and corrosion resistance. In this blog, we will delve into the mechanical properties of 5086 aluminium coil, its weldability, and the various applications that benefit from this versatile alloy.
Introduction to 5086 Aluminium Coil
5086 aluminium coil is a non-heat-treatable alloy belonging to the 5000 series, which primarily consists of aluminium with magnesium as the major alloying element. This composition grants it exceptional resistance to seawater corrosion, making it one of the preferred choices for marine and structural applications.
Chemical Composition of 5086 Aluminium Coil
- Aluminium (Al): 93.0 – 96.9%
- Magnesium (Mg): 3.5 – 4.5%
- Manganese (Mn): 0.2 – 0.7%
- Iron (Fe): 0.5% max
- Silicon (Si): 0.4% max
- Chromium (Cr): 0.05 – 0.25%
- Copper (Cu): 0.1% max
- Zinc (Zn): 0.25% max
The presence of magnesium and manganese enhances the alloy’s strength and resistance to stress corrosion cracking, making it a top choice in demanding environments.
Mechanical Properties of 5086 Aluminium Coil
5086 aluminium coil exhibits a unique combination of mechanical properties that make it ideal for high-performance applications. Below are its key mechanical characteristics:
1. Strength and Hardness
5086 aluminium coil has moderate to high strength, making it suitable for structural applications. Though it is not as strong as some heat-treated alloys (like 7075 or 6061), it offers an excellent balance between strength and corrosion resistance.
Tensile Strength
- Annealed (O Temper): ~275 MPa (40,000 psi)
- H32 Temper: ~310 MPa (45,000 psi)
- H116 Temper: ~345 MPa (50,000 psi)
Yield Strength
- O Temper: ~125 MPa (18,000 psi)
- H32 Temper: ~220 MPa (32,000 psi)
- H116 Temper: ~260 MPa (38,000 psi)
These values demonstrate that 5086 aluminium coil can withstand significant loads, making it ideal for marine, aerospace, and structural applications.
2. Toughness and Impact Resistance
5086 aluminium coil maintains high impact resistance even in low temperatures, which is crucial for marine applications where materials are exposed to varying environmental conditions. Unlike brittle materials, 5086 remains ductile and resilient, preventing sudden failure under heavy stress.
3. Corrosion Resistance
One of the standout properties of 5086 aluminium coil is its exceptional resistance to corrosion, particularly in marine and industrial environments. The high magnesium content enhances its ability to resist saltwater corrosion, pitting, and stress corrosion cracking.
This feature makes 5086 aluminium coil a preferred material for boat hulls, shipbuilding, and offshore structures, where prolonged exposure to seawater is inevitable.
4. Formability and Ductility
5086 aluminium coil is known for its good formability, making it suitable for bending, rolling, and shaping without cracking. It can be cold-worked to achieve different tempers (H32, H116, etc.), enhancing its mechanical properties while retaining ductility.
Weldability of 5086 Aluminium Coil
1. Excellent Weldability with Various Techniques
One of the biggest advantages of 5086 aluminium coil is its exceptional weldability, making it highly suitable for fabrication and assembly. It can be welded using common welding techniques such as:
- TIG (Tungsten Inert Gas) Welding
- MIG (Metal Inert Gas) Welding
- Resistance Welding
- Friction Stir Welding (FSW)
5086 is a non-heat-treatable alloy, meaning that welding does not significantly affect its strength. This is a major advantage over heat-treatable alloys like 6061, which lose strength in the heat-affected zone.
2. Avoiding Weld Cracking
5086 aluminium coil has good resistance to weld cracking due to its high magnesium content. However, to optimize weld quality, the following precautions should be taken:
- Use appropriate filler metals (e.g., 5356 or 5183) to enhance strength and corrosion resistance.
- Pre-clean the surface to remove oxides and contaminants before welding.
- Control heat input to avoid excessive softening.
Applications of 5086 Aluminium Coil
Given its impressive strength, weldability, and corrosion resistance, 5086 aluminium coil is widely used across various industries. Some of its major applications include:
1. Marine and Shipbuilding Industry
5086 aluminium coil is a top choice for marine environments due to its excellent resistance to saltwater corrosion. It is commonly used in:
- Boat hulls and superstructures
- Yachts and fishing vessels
- Docks and offshore platforms
- Storage tanks for marine fuel and chemicals
2. Aerospace Industry
In the aerospace sector, 5086 aluminium coil is used in fuel tanks, pressure vessels, and structural components, where a combination of strength and lightweight properties is essential.
3. Automotive and Transportation
The automotive industry leverages 5086 aluminium coil in truck bodies, trailers, and rail cars, where weight reduction is a priority for fuel efficiency without compromising structural integrity.
4. Defense and Military Applications
5086 aluminium coil is widely used in armor plating for military vehicles, ballistic-resistant panels, and defense infrastructure due to its high strength and impact resistance.
5. Construction and Infrastructure
- Bridges and pedestrian walkways
- Structural frames for buildings
- Cryogenic storage tanks (due to its ability to withstand low temperatures)
Conclusion
5086 aluminium coil is a versatile, high-strength alloy that excels in weldability, corrosion resistance, and mechanical performance. Its ability to withstand harsh environmental conditions, particularly in marine, aerospace, and defense applications, makes it a valuable material in various industries.
With its excellent balance of strength, durability, and fabrication ease, 5086 aluminium coil continues to be a go-to choice for engineers and manufacturers worldwide. Whether you’re building a ship, a fuel tank, or a structural component, 5086 aluminium coil provides long-term reliability and performance.