About aluminium 6061 – Ideal for engineering and structural applications
Aluminium 6061 and 5052 are fairly similar, but 6061 is a lot stronger thanks to being a heat-treatable alloy. Loved for its many useful features, it is used more often than 5052 in engineering and structural applications. Here’s a run-down of the features of aluminium 6061.
What is aluminium 6061?
First created in 1935 and originally called Alloy 61S, this metal is often used for projects where welding or brazing is necessary. One of the most versatile heat-treatable alloys, 6061 aluminium alloy is available in plate, bar, and tube formats, great for structural applications, boats, and household goods. It is very versatile thanks to the blend of magnesium and silicon, known for its strength, formability, weldability, join-ability, machinability, and resistance to corrosion. In fact, once treated with heat it’s just as strong as low carbon steel.
How is aluminium 6061 made?
6061 is what’s called a’ precipitation-hardened’ aluminium alloy, with magnesium and silicon as the major alloying elements. This is one of the commonest alloys of aluminium for general use, usually available in pre-tempered grades like 6061-O, which is annealed, plus tempered grades like 6061-T6, which is solutionised and artificially aged. There’s 6061-T651, which is solutionised, stress-relieved stretched, and artificially aged and even 6061-T6, a very pure alloy with 95.85%–98.56% total aluminium content.
More elements can be added to change the material’s hardness and durability, including:
- A minimum 0.4% silicon and a maximum of 0.8%
- A minimum of 0.15% copper, maximum 0.40%
- A minimum 0.04% chromium, maximum 0.35%
- Zinc to a maximum of 0.25%
- Titanium to a maximum of 0.15%
Why was aluminium 6061 invented?
Firstly, the metal offers great corrosion resistance. When exposed to moisture or air, 6061 aluminium alloy creates an oxide layer that makes it impossible for the metal to react with corrosive elements. The amount of corrosion resistance depends on the amount of water in the atmosphere and the ambient temperature.
The copper content of 6061 means it is a tiny bit less corrosion resistant than some alloys, including the copper-free 5052 alloy. 6061 resists corrosion from strong nitric acid, ammonia, and even ammonium hydroxide better than most, and you can easily coat the alloy with a protective layer to make it 100% corrosion-free.
6061 aluminium alloy is very strong, with a yield tensile strength of 276 MPa (40000 psi), and an ultimate tensile strength of 310 MPa (45000 psi).
It was created to deliver good shear strength, which makes it a star in the world of torsion applications like shafts and bars, which can get twisted. The shear strength of 6061 aluminium alloy is 207 MPa (30000 psi).
Good fatigue strength is another valuable feature, namely the ability to resist breaking under cyclical loading with a small load made repeatedly. This means it’s perfect for jobs with repetitive loading cycles, for example the pistons in an engine.
What is aluminium 6061 used for?
Type 6061 is one of the most popular aluminium alloys thanks to its weld-ability and formability, high strength and corrosion resistance. Some of its most popular applications are:
- Motor vehicles
- Welded assemblies
- Frames, fittings and hardware for ships and boats, aircraft, railways, and heavy vehicles
- Chemical equipment
- Electronic parts
- Heat exchangers and heat sinks
- Stairs, flooring, and ramps
- Hydraulic pistons
- Awnings and mouldings
- Appliance fittings
- Food Service and food containers
- Scuba diving tanks
- Bike frames
- Components for bridges
- Mounts for camera lenses
- Electrical fittings and connectors
What affects the price of aluminium 6061?
The cost of the raw aluminium affects the cost of aluminium 6061, as do the prices of the alloy metals used to create it. Covid lockdowns in mining and producing nations can delay production as well as international deliveries, and when trade wars erupt, as they did during the Trump administration, political tension can also affect supply.
Buy aluminium 6061
Do you need aluminium 6061 or 5052? As expe4rts in metals we can help you with that decision, and we’ll always pull out all the stops to get you the UK metals supplies you need.
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