This is a copper-aluminium bronze containing 10wt% aluminium. A small amount of iron is often added to act as a grain refiner to improve the mechanical properties.

Alloys with more than 8wt% aluminium solidify as the beta phase. Below about 930°C, Widmanstatten alpha phase precipitates. At the eutectoid temperature (565°C) the remaining beta decomposes to a lamellar eutectoid of alpha and beta. Rapid cooling from the high temperature beta phase can form martensite instead of Widmanstatten alpha.

Aluminium bronzes have high strength, corrosion resistance and good high temperature properties (up to 300-400°C). Typical applications include bearings, gears and corrosion resistant vessels.