Magnesium is the lightest of all metal elements and is used primarily in structural alloys because of its light weight, strength and corrosion resistance and is abundantly available in the earth's crust and seawater.
After steel and aluminum, magnesium is the most widely used structural metal. With a density about one-fourth that of steel and two-thirds that of aluminum, magnesium offers excellent potential for lightweight applications in the transportation (land, air and sea), and energy and industrial sectors.
Casting is one of the main manufacturing processes for the production of magnesium parts, and in recent years more and more products made of forged magnesium (extrusion, forging and plate) have been applied.
Magnesium's properties are similar to those of its sister metal aluminum. Not only does it have the lowest density of any metallic element, making it the lightest, but it is also very strong, highly resistant to corrosion and easy to work with.
Magnesium was discovered as a unique element by Sir Humphrey Davy in 1808, but not produced in metallic form until 1831 when Antoine Bussy made magnesium during an experiment with dehydrated magnesium chloride.
Commercial production of electrolytic magnesium began in Germany in 1886. The country remained the sole producer until 1916, when military demand for magnesium (for flares and tracer bullets) led to production in the U.S., Britain, France, Canada and Russia.
Between the wars, world production of magnesium declined, although German production continued to support the Nazi military expansion. German production rose to 20,000 tons in 1938, accounting for 60% of world production.
To catch up, the U.S. supported 15 new magnesium production facilities, and by 1943 it had a production capacity of more than 265,000 tons of magnesium.
After World War II, magnesium production fell again as producers struggled to find economical methods of extracting the metal to make the price competitive with the cost of aluminum.
Depending on the location and type of feedstock used, a wide range of production methods can be used to refine magnesium metal. This is due partly to the fact that magnesium is so abundant, making production possible in many locations, and partly to the fact that the end uses of the small metal are so price sensitive that buyers are constantly looking for the lowest possible cost source.
Traditionally, magnesium has been produced from dolomite and magnesite ore and magnesium chloride-containing salt brines (naturally occurring salt deposits).
More than half of all magnesium is used in alloys with aluminum, which are valued for their strength, lightness and resistance to sparks, and are widely used in automotive components. Several auto manufacturers use magnesium-aluminum (Mg-Al) die-cast alloys to produce steering wheels, steering columns, support brackets, instrument panels, pedals and housings for intake manifolds, among countless other parts. Mg-Al die castings are also used to make transmission and clutch housings.
High strength and corrosion resistance are essential for aerospace alloys and gearboxes for helicopters and race cars, many of which use magnesium alloys.
Beer and soft drink cans do not have the same requirements as aerospace alloys, yet a small amount of magnesium is used in the aluminum alloy from which these cans are made. Despite using only a small amount of magnesium per can, this industry is still the largest consumer of the metal.
Magnesium alloys are also used in other industries where lightweight, solid alloy applications are crucial, such as in chainsaws and machine parts, and in sporting goods such as baseball bats and fishing reels.
Other uses of magnesium include as an anode for cathodic protection in chemical storage tanks, pipelines and ships, and in the production of flare bombs, incendiary bombs and fireworks.