Magnesium is a silvery-white metal that is light in weight yet strong in nature. With an atomic number of 12, magnesium is the eighth most abundant element in the Earth’s crust and the third most abundant element dissolved in seawater. Magnesium has a hexagonal close-packed crystal structure which allows it to readily deform plastically without breaking. This property of plasticity along with its low density of 1.738 grams per cubic centimeter gives magnesium excellent castability and mechanical properties. It has a melting point of 650°C and a boiling point of 1,090°C. Magnesium is highly flammable when powdered or in ribbon form and readily oxidizes in air producing a brilliant white light.
Applications of Magnesium metal
One of the major applications of magnesium is in the automotive industry where it is used to manufacture both engine parts and vehicle bodies. Magnesium alloys reduce vehicle weight significantly helping improve fuel efficiency. Reduced weight also improves vehicle performance and handling. Engine components like intake manifolds, oil pans and transmission cases are commonly made from die-cast magnesium alloy. Exterior auto parts including wheels, doors and deck lids utilize magnesium sheet metal. Reduction in vehicle weight by 100 pounds saves over 1 gallon of fuel over 5,000 miles of driving.
In the electronics industry, Magnesium Metal finds application in manufacturing laptop, tablet and smartphone cases and frames. The low density of magnesium makes for lighter devices that are also durable. Computer components such as housings and brackets also use die-cast magnesium alloys. In aviation and aerospace applications, magnesium alloys are employed to make aircraft and spacecraft frames, engine casings and helicopter gearboxes. Thanks to its high specific strength to weight ratio, magnesium helps aviation achieve greater fuel efficiency and thrust-to-weight performance.
Another major use of magnesium metal is to produce industrial machine parts used across various industries. Components like pulleys, housings and brackets benefit from magnesium’s strength and machinability properties. In the construction industry, it is used to make formwork frames and scaffolding parts where lightweight yet durable structures are required. Magnesium alloys are highly decorative and thus used to produce external architectural cladding as well as roofing and rainwater drainage systems. In the field of biomedicine, implantable devices use biodegradable magnesium alloys as support structures that dissolve over time in the human body.
Production and Processing of Magnesium
Nearly all magnesium produced nowadays is extracted from sea water or brines containing magnesium chloride. However, historically it was obtained by thermal reduction of magnesium oxide (magnesia) or magnesium chloride. The two dominant industrial processes for magnesium production are the Pidgeon process and the electrolytic process.
In the Pidgeon process, calcined dolomite (CaMg(CO3)2) or magnesite (MgCO3) is mixed with ferrosilicon and subjected to thermal reduction in a submerged arc furnace at 1,200-1,500°C. The end products are magnesium vapor and magnesium silicide slag. The Magnesium Metal is then condensed and cast into ingots.
In the electrolytic process, seawater or brine is purified to extract pure magnesium chloride which is then electrolyzed using the Downs cell method. In this method, magnesium chloride is electrolyzed between an anode and cathode in a molten salt electrolyte mixture containing magnesium chloride and calcium chloride. Magnesium metal settles to the bottom and is periodically drained off.
Post-processing techniques work magnesium into useful products and parts. Common magnesium alloying elements are aluminum, manganese, zinc, zirconium and rare earth metals. Alloys are produced by melting, casting, powder metallurgy or other sintering processes followed by heat treatments and mechanical working. The final net or near-net shape parts are produced by die-casting, sand casting or permanent mold casting methods.
Future Prospects for Magnesium
Magnesium metal usage is expected to grow significantly in the coming years mainly driven by the automotive industry’s focus on lightweight materials to meet fuel economy and emissions standards. Other transportation sectors including aviation and rail are increasingly adopting magnesium alloys in airframes, landing gear and railcar bodies. In the consumer electronics industry as well, magnesium alloys offer the dual advantages of strength and low weight that can facilitate portable device miniaturization. Areas such as biomedical implants are exploring new magnesium alloy compositions and surface modification techniques to further improve biocompatibility. The future also holds promise for more sustainable magnesium production using renewable energy sources and recycling of scrap magnesium. Overall, magnesium’s compelling strength-to-weight ratio profile makes it an integral part of strategic lightweighting initiatives across many technology frontiers.
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1. Source: Coherent Market Insights, Public sources, Desk research
2. We have leveraged AI tools to mine information and compile it
