Wrought Magnesium

Magnesium is very abundantly available, for example in sea water. The extracting process however takes a large amount of energy: 72 MJ/kg Mg, which makes it relatively expensive. Magnesium has a density even lower than Al. However also the Young's modulus is lower than that of Al, hence stiffness must be achieved by design. Mg is not covered by a protective oxide layer, but oxidation rates are normally low. In wet environments protection is necessary (anodising, coating).  Mg has a HCP crystal lattice an hence cold forming possibilities (e.g. to enhance strength) are poor. Between 220C and 400C (hot) deformation is possible. In general, alloying is done to increase mechanical properties. Wrought alloys usually contain less of alloying elements than cast. The wrought structure generally offers better mechanical properties than cast, because of anisotropy.