6 - Magnesium Alloys

Abstract

This chapter covers cast and wrought magnesium alloys and describes current trends in their commercial applications. Solid solubilities of the commonly used alloying elements are considered with respect to their effects on melting and casting with special reference to the beneficial grain refinement that can result from the addition of small amounts of zirconium. Emphasis is placed on how other alloying elements influence the as-cast microstructures, response to age hardening, mechanical properties, and corrosion resistance of sand castings and high-pressure die castings. Attention is then given to wrought magnesium alloys and how alloying elements may also influence formability, extrudability, and mechanical properties. Fabrication of products is discussed with particular reference to joining methods and the exceptional machinability of magnesium alloys. Some current applications of both cast and wrought magnesium alloys are then described in the aerospace, automobile, medical, and superconducting industries.