Magnesium, like most pure metals, is not sufficiently strong in its pure form so it must be alloyed with other materials in order to gain higher strength to weight ratio. Susceptibility to corrosion can be reduced through alloying magnesium. Ductility of alloys is also higher than pure magnesium because alloying increases the number of active slip planes within the material. Common alloying elements are aluminum, zinc, manganese, and some rare earth metals. Ceramic particles or fibers can also be added to magnesium to help increase strength.
- The first one or two letters indicate the alloying elements used in the greatest quantity.
- Two or three numbers denote the rounded off percentage present of these principal alloying elements.
- The following letter indicates the variation from one subsequent alloy to another with only minor difference in composition.
- Heat treatment codes may appear hyphenated on the end of the designation. These codes follow the same system as aluminum alloys.
F – as fabricated
O – Annealed (from cold worked or cast state)
H – Strain hardened by cold working (for wrought products only)
H1 – Strain hardened only
T – Heat treated
W – Solution treated only (unstable temper)