Aluminium is an attractive metal due to its low density, high specific strength and good corrosion resistance. It is used extensively in aerospace engineering, automobile manufacturing and weapon production. However, the lack of a fatigue limit for aluminium alloys makes them unsuitable for parts that are exposed to repeated stress cycles. In such applications, steel components can be used, but these are considerably heavier than their aluminium counterparts. The invention provides a novel aluminum-manganese alloy which can be used for lightweight component construction while maintaining the corrosion resistance of aluminium.

The novel almn alloy consists of mainly aluminium (Al) and manganese (Mn). Other elements such as iron (Fe), silicon (Si), magnesium (Mg) or copper (Cu) are present to a lesser extent. The alloy is wrought and can be processed into sheets or profiles using rolling or extrusion presses.

This is possible due to the special microstructure of the alloy, which combines a matrix of the b-phase and a dense g-phase precipitate. The globular third precipitates 33 of the g-phase can be clearly seen at a magnification of about 20 times as bright particles in the b-phase matrix 2.

This microstructure ensures excellent machinability, and the alloy also has a low fracture sensitivity at elevated temperatures. In a standardized endurance test in a ring segment disc tribometer, a specimen of the alloy according to the invention showed after 6 hours of testing at 120 deg C practically no wear. This is a significant improvement over known copper-based plain bearing alloys with similar hardness.