Areas of Application of Magnesium
Innovative Uses for Magnesium Die Castings
Magnesium die castings have an enormous field of application: Many different engineering disciplines benefit from the special material properties of this nonferrous metal.
Magnesium is one of the lightest and most pliable metals used in alloy die casting and machining today. While pure magnesium is too volatile, combustible, and corrosive to be used in its purest form, magnesium can be combined with other lightweight metals such as aluminum to be die cast into almost any shape or texture. These compound materials offer excellent potential for thin-wall and complex structure formation, making them a leading choice for use in projects requiring more delicate work. As it is commonly considered to be the eight most common element in the earth's crust, the cost-to-material ratio also makes it an attractive choice for use in bulk machining work or mass production. It is the lightest alloy (in terms of mass) commonly cast in modern die molding.
Magnesium-aluminum alloy products, most commonly the material AZ91D, are used frequently in industrial and consumer products as EMI and RFI shielding, vehicle parts, and as structural components. However, the metal's high heat resistance, excellent electrical conductivity, and 100% reclamation rate when it is recycled make it extremely versatile. As aluminum shares many of the same properties as the light metal it is often favored for use in combined die casting. However, magnesium can be combined with many other diecast metals.
How does die casting work?
In this case, die casting is performed by injecting a liquid, molten magnesium alloy into a fixed mold using a 'cold' injection device, known as a Cold-Chamber. Cold-chamber processing is slower, but it means that magnesium can be combined with higher melting point metals such as aluminum and copper by melting it in a separate furnace. The metal is then infused and injected into a two-sided self-ejecting mold to form and cool. Diecast materials can be combined, enhanced, or modified post-completion to form complex components through finishing operations or additional fixing or welding.
There are many more applications than just creating engine casings that an engineer can apply when die casting lightweight alloys. Below are just a few of the more interesting uses that a well-managed compound could be put to with the right cutting-edge know-how.
Automotive casing and components
The most common use today for diecast alloy components is in high-performance cars. As casted alloy components are lightweight, aerodynamically smooth, and can be fitted to most frames easily, cutting-edge sportscars frequently incorporate light-alloy components and shell casings to cut down on weight and increase vehicle speed and fuel efficiency. Light alloy casing is environmentally friendly, too. Increased efficiency can lead to significant reductions in CO2 emissions per vehicle. Advances in part molding for mass producing aluminum components to replace traditional steel fixtures and fittings may mean that average fuel consumption could be reduced per vehicle by 12% by 2050 (USAMP estimates). It is also a popular choice of material for gearboxes and steering wheels. This is due to the ease of movement and precise tooling that molding can give when working on smaller finished pieces.
Electronic casing and housing
Magnesium alloys can form a great shield against electromagnetic and radio interference, despite their high conductive qualities. It's for this reason that more and more manufacturers are choosing to fit laptops, tablets, phones, and televisions with a magnesium alloy protective casing. With an increasingly crowded spectrum environment, a growing demand for recyclable consumer products, and the cheapness and availability of the light metal, an alloy finished case may soon be the default choice for most portable electronics.
Aerospace and space exploration
The diecast alloy's insulative properties and lightweight constructions also make it ideal for use in aircraft, missiles, rockets, and spacecraft. Its durable properties make it ideal for use in high altitude, low oxygen, low-temperature flight. Diecast magnesium-aluminum alloys are also used extensively to strengthen the flexibility and durability of fuel transfer systems, engine fuel injectors, and jet engine casings in commercial passenger aircraft. Due to the increased focus by American space exploration agencies on 'big booster' targets such as crewed Mars missions, light metal alloy molded casing and parts may become more common in rockets. Similar components have dominated ICBM construction with nuclear deterrent brands in previous decades, such as with Titan and Atlas missiles.
One unusual and surprising new use of the molded alloy is in the creation of dissolvable medical fittings and internal braces for surgery. As the light metal is naturally found within the human body, pure molded implants will slowly be assimilated. This has made bone and organ realignment less invasive and expensive, as only one operation is required to make the correction.
Other household items
Magnesium-aluminum alloys are just a good overall material choice for the general construction of hard-wearing metallic items. Some combined diecast alloy consumer items commonly found include stepladders, luggage containers such as suitcases, power tools, brackets, and bicycles.