Choosing the Right Alloy

Created using roughly 95% aluminium (Al), 4.5% copper (Cu) and 0.5% other materials, 2000 series alloys are typically used in a similar fashion to steel but come with added weight, corrosive and shaping benefits. 

Benefits

• Although more corrosive than other aluminium alloys, they can still outlast steel significantly
• High malleability means the profiles can be shaped and sized in ways steel simply cannot
• Up to 2.5 times lighter than their steel equivalent

Draw Backs

• Often requires cladding as they are more susceptible to corrosion compared to other alloys
• Their light weight comes at the cost of strength, sometimes requiring thicker profiles
• Generally more expensive than steel

These alloys are by far the most versatile and commonly used in the industry for extrusion. This is due to the wide range of options available, making picking specific characteristics much easier.

Benefits

• Highly heat treatable, adding the possibility to strengthen profiles significantly and making them suitable for multiple construction and structural applications
• Anodising can produce far more aesthetically pleasing finishes than other metals, making them ideal for interior design and architectural purposes 
• Finished and anodised profiles are virtually invulnerable to corrosion, even in extremely harsh environments, such as under-water  
• It's easy to weld with

Draw Backs

• Whilst strong, 6000 series alloys cannot achieve the same strength as a 2000 or 7000 series alloy

As the strongest series alloy available, 7000 series aluminium is mostly used for construction but is also present in the automotive and aerospace industries as well.

Benefits

• Very good strength relative to other alloys, and will maintain it's level for strength for longer
• More resistant to heat, maintaining the afore-mentioned strength where other alloys may not
• Ideal for anodising, although mainly for protective properties

Draw Backs

• Not as visually pleasing as 6000 series alloys as their strength limits anodising capabilities
• Due to their strength, 7000 series alloys are difficult to extrude and limit profile complexity
• They have a lower corrosive resistance than 6000 series alloys, although this can be improved by adding other materials

Usually, at-least 99% aluminium, 1000 series alloys are the purest available. These are non-heat-treatable, and therefore much weaker than any of the extrudable alloys.

Benefits

• Good heat and electrical conductivity
• High corrosion resistance
• Easily mouldable

Draw Backs

• Typically very weak, although moderate improvements can be made via cold working
• Non-heat treatable

Moderately stronger than 1000 series alloys, 3000 series is commonly used to produce household items such as kettles and pans. This strength is achieved by adding some manganese to the alloy.

Benefits

• Equal heat and electrical conductivity to 1000 series
• Equally high corrosion resistance
• Only marginally less mouldable, although with slightly more strength

Draw Backs

• Still weak compared to other aluminium alloys
• Non-heat treatable

By adding silicon to the alloy, 4000 series aluminium obtains a beneficial electro-magnetic resistance, making it ideal for producing hard-drive trays or welding wire, for example.

Benefits

• Good electromagnetic resistance
• Ideal thermal and electrical conductivity
• High corrosion resistance

Draw Backs

• Difficult to machine, mould and shape due to the brittleness of the silicon