How to Select Magnesium and Magnesium Alloys
Magnesium and magnesium alloys are nonferrous metals with low density, good ductility, moderate strength, and good corrosion resistance.
Types of Magnesium and Magnesium Alloys
Magnesium is a silvery-white, light-weight metal that is relatively strong and tarnishes some through air contact. While it is hard to combust in bulk solid form, it is highly volatile in shavings or strips and has the ability to burn in nitrogen, carbon dioxide, and water.
Magnesium Alloys and Materials
Magnesium based-alloys are often named by two letters followed by two numbers. Letters represent the alloying metal additions and the numbers correspond to the weight percent of each metal (respectively) in the compound. They can be divided into two main categories of alloys: casting alloys and wrought alloys.
- Casting alloys are alloys manufactured by die casting, permanent mold casting, and sand casting methods. Mechanical properties (particularly ductility) of cast alloys are lower than those of wrought alloys. Cast magnesium alloys, particularly magnesium-aluminum alloys are used in manufacturing aircraft and automobile parts due to their low density and light weight properties.
- Wrought alloys are alloys that have been worked or forged to particular shapes. The ductility of magnesium alloys in the cold state is low and thus these alloys are worked at hot temperatures. They are typically combined with manganese, aluminum, zinc, or zirconium for different applications. Manufacturing uses range from aircraft fuselages and helicopter gears to computer cases and bicycle frames.
Selecting metal alloys requires an analysis of the desired dimensions and specifications. Dimensions to consider include outer diameter (OD), inner diameter (ID), overall length, and overall thickness. Other specifications of importance (based on application) include product shape, tensile strength, yield strength, melting point, conductivity, corrosion resistance, ductility, and malleability. These properties differ based on the forming method and alloy composition.
Applications and Uses
Magnesium and magnesium alloys are used in applications that require light weight, low density, heat resistance, and good to excellent corrosion resistance. It is most commonly known for its use in the aerospace industry but also has applications in bicycles, the automotive industry (especially for motor racing), electronics, the nuclear industry, flash photography, flares, sporting goods, and tools.