Magnesium is a metal that has many desirable properties, including high strength/weight ratio, good corrosion resistance and low density. It is used in a variety of applications, including bicycles, automotive (especially motor racing), aerospace, nuclear industry, flash photography and flares, and construction. The main disadvantage of magnesium is its reaction with oxygen, which means that it must be stored in an atmosphere where oxidation cannot occur.
Wrought magnesium aluminum alloys have moderate strengths, high plasticities and appropriate corrosion resistance. They can be further strengthened through a baking hardening treatment. In wrought alloys the structure is a mixture of primary crystals, called dendrites, and secondary crystals, which are referred to as clusters or lamellae.
The primary crystals form a close-packed hexagonal crystalline structure which restricts slip on the main planes at room temperature, thus making the material very elastic. This characteristic also contributes to the excellent ductility of magnesium alloys.
Magnesium is the key element that controls mechanical properties, but all other alloying elements influence them as well. The properties of a wrought alloy depend on its composition and forming method:
Magnesium alloys can be made into a wide range of shapes, such as bars, forgings, plates, sheets and welding wires. They are also available as extrusions and castings. Magnesium alloys are produced in different compositions for the aeospace, defense, automotive, and manufacturing industries. Some of the most common magnesium alloys are AZ31B, AZ61, and AZ80.