The use of aluminium bronze in metal casting

Published - 22nd Mar 2017

In earlier blogs, we’ve looked at the benefits of using both aluminium and copper in our casting work. In this blog, we will be looking more specifically at the use of aluminium bronze – in which aluminium is the main alloying metal added to copper.

Aluminium bronzes contain varying amounts of aluminium, usually ranging from 5 to 11 per cent. Other metals, such as copper, iron, nickel, manganese and silicon, are added to enhance the mechanical and physical properties.

Aluminium bronze offers some valuable characteristics, including:

• high strength
• excellent corrosion and wear resistance
• high thermal and electrical conductivity
• non-sparking benefits

It is a popular choice for many industrial applications, ranging from landing gear components on aircraft through to ship propellers and even jewellery.

The key benefits

Aluminium bronze offers the highest strength of all the copper-based alloys – with similar physical properties to mild steel. Most notably, it has exceptional corrosion resistance. This is because aluminium in the alloy reacts with oxygen in the atmosphere to form a thin, yet tough, surface layer of aluminium oxide. The aluminium oxide acts as a barrier to corrosion.

For this reason, aluminium bronze is widely used in marine and offshore environments in propellers, underwater fastenings, valves and pumps. Indeed, many ships’ propellers are made using this material.

Another important feature is the alloy’s biostatic effects in water – which means that it inhibits the growth of algae, lichen, barnacles and mussels. Ships hulls are often coated with aluminium bronze for this reason, helping to reduce maintenance costs and improve efficiency.

High industry demand

Aluminium bronze is in high demand in the oil and gas industries and in hazardous environments – due to its non-sparking properties. It is also becoming increasingly popular in the building and architectural sectors. Although more expensive to buy than some materials, aluminium bronze is relatively low maintenance – which offers savings in the long run. Aluminium bronze is also the most tarnish resistant of all the copper alloys so it also offers many aesthetic benefits too.

Aluminium bronze at Haworth Castings

At the foundry, we use aluminium bronze for a range of sand casting work due to its strength and excellent corrosion resistance.

Please get in contact if you would like to find out more about the alloys used in our sand casting and gravity-die casting. Email: sales@haworthcastings.co.uk or call +44 (0)1794512685.