They consist mainly of aluminium (Al); in addition to manganese, which accounts for the largest proportion of about 1% of the alloying elements, but they may also contain small amounts of iron (Fe), silicon (Si), magnesium (Mg), or copper (Cu).
AlMn is almost only used as a wrought alloy and is processed into sheets or profiles by rolling or extrusion presses.
Aluminium–manganese alloys are used in applications with low strength requirements and also in chemical and food-related environments due to their corrosion resistance.
Magnesium and copper are more effective in enhancing strength, providing an increase of 70–85 MPa per % of Mg when added to the alloy.
The structure resulting from casting into bars or slabs consists of the main mass, which is an oversaturated mixed crystal, along with areas containing manganese-containing phases that have an average size of about 100 μm.
During this transformation, various phases that were previously present within the basic aluminium crystal structure, each having a size of less than one micron, are eliminated.
However, it's important to note that this improvement is relatively modest, as the influence of grain size on the strength of aluminium materials is generally limited.