Aluminum is one of the most popular and commonly used metals in manufacturing. Its main advantage over steel is its corrosion resistance. Unlike steel, aluminum does not rust or corrode when exposed to air, water and moisture. Its outer passivation layer, or oxide coating, protects it from corrosion and oxidation.
It is also light and very strong. This makes it the ideal material for many structural applications that require a high strength-to-weight ratio.
In addition, aluminum has excellent ductility that allows it to bend and form into different shapes without breaking. This is important for manufacturing processes like extrusion and rolling.
An impurity of iron lowers the ductility of aluminum. This can be problematic because it can cause bending failures or distortion when the aluminum is under load.
Fortunately, this impurity can be avoided by adding aluminum to iron to make an alloy called ferro aluminum. These master alloys have a variety of uses, including deoxidation, welding fluxes, wires and hardfacing.
Zinc (Zn) 7xxx – The addition of zinc to aluminum in conjunction with other elements, primarily magnesium and copper, produces heat-treatable aluminum alloys of the highest strength. These alloys can be fusion welded or mechanically formed, depending on the application.
Manganese (Mn) 3xxx – The addition of manganese to aluminum increases strength somewhat through solution strengthening and improves strain hardening while not appreciably reducing ductility or corrosion resistance. These moderate strength nonheat-treatable aluminum alloys are seldom used for major structural applications.