Magnesium Alloys: The Lightest Structural Metal

Magnesium (density 1.74 g/cm3, about 35 percent that of steel and 65 percent that of aluminium) is the lightest structural metal, attractive for weight-critical transport. Commercial alloys are based on Al, Zn, Mn (AZ, AM, AS series) and the rare-earth-containing WE and ZEK families. Polmear (1994) reviewed their metallurgy and applications; Mordike and Ebert (2001) summarised properties and potential, including die-cast AZ91D and wrought AZ31B.

Strengthening is by solid solution (Al, Zn), precipitation (Mg17Al12, or rare-earth phases in WE43) and grain refinement. Magnesium's hexagonal lattice gives limited room-temperature formability, so most parts are die-cast; wrought AZ31/WE43 need warm forming. Corrosion (especially galvanic) must be managed by coating and isolation from dissimilar metals.

For buyers, AZ91D die castings suit housings; AZ31B sheet/extrusion suits brackets; WE43 serves aerospace/BIW. JLHSteel supplies magnesium plate, sheet and forgings and can advise on joining and protection.

References
1. Polmear, I.J. (1994). Magnesium alloys and applications. Materials Science and Technology 10(1): 1-16. https://doi.org/10.1179/026708394790072166
2. Mordike, B.L., Ebert, T. (2001). Magnesium: properties - applications - potential. Materials Science and Engineering A302(1): 37-45. https://doi.org/10.1016/S0921-5093(00)01351-2
3. Aghion, E., Bronfin, B. (2000). Magnesium alloys development towards the 21st century. Materials Science Forum 350-351: 19-28.