Because of their low modulus of elasticity, magnesium alloys can absorb energy elastically. Combined with moderate strength, this provides excellent dent resistance and high damping capacity. Magnesium has good fatigue resistance and performs particularly well in applications involving a large number of cycles at relatively low stress. The metal is sensitive to stress concentration, however, so notches, sharp corners, and abrupt section changes should be avoided. However, what is true of magnesium as a generic material is not true of today's die-casting alloy.
Magnesium alloys are the easiest of the structural metals to machine.
They can be shaped and fabricated by most metalworking processes, and they are easily welded. Pure magnesium is usually alloyed with other elements to develop sufficient strength for structural purposes. Some alloys are heat treated to further improve properties. Permanent-mold castings are as strong as sand castings, and they generally provide closer dimensional tolerances and better surface finish. Typical applications of magnesium gravity castings are aircraft engine components and wheels for race and sports cars.