Magnesium Alloy
Magnesium is considered to be the lightest structural material. Magnesium alloy is the mixtures of magnesium, with other metals called an alloy; aluminum, zinc, manganese, silicon, copper, rare earths and zirconium. Magnesium alloy will have a hexagonal lattice structure, which will affect basic properties of these alloys. In many components of modern cars, cast magnesium alloys are used and in some high performance vehicle also magnesium block engines have been used. For camera bodies and components in lenses, die cast magnesium is used. ASTM 275 (American society for testing and materials) defines magnesium alloys to refer by short codes denoting the approximate chemical composition of weight. For an e.g. AS41, it has 4% Al and 1% silicon. If Al is present, manganese is almost there at about 0.2% by weight to gain structure and for the same purpose Zirconium will present, if Al and manganese are absent.
Key properties:
It is light in weight compared with others, the density is low (2/3 that of aluminium), Good high temperature mechanical properties, and Excellent corrosion resistance.
Applications:
Aerospace
For helicopter casing, RZ5 alloy have been used for many years, due to the combination of low density and good mechanical properties. RZ5 alloy was used for gearbox casing in the past, but new programmers’ will use WE43 instead of including main rotor gear box castings. The applications of WE43 will go ahead in the future and also to replace RZ5 on older rotorcrafts. For aircraft engines and gearbox casings RZ5, ZRE1, MSR and EQ21 alloys are widely used. But for its corrosion and high temperature properties, WE43 will be used increasingly. In intermediate compressor casing for turbine engines, very large magnesium castings can be made. Other aerospace application includes auxiliary gearboxes in MSR or RZ5, generator housings and canopies, generally in RZ5. Magnesium forgings are likely to be used in higher temperature applications in future. These ways magnesium alloys are used in aerospace.
Automotive motor racing
RZ5 is mostly used for gearbox casings in motor racing, even though MSR alloy is being used increasingly because of their ambient temperature properties. When compared with Mg-Al-Zn alloy wheels, RZ5 wheels have been shown to have better performance under arduous racing conditions. WE54 castings have been used for various formula 1 engine parts, due to the high operating temperature of racing engines, and are used for engine components for a limited edition road car. Forged WE54 pistons will surely offer great future potential for motor racing and other applications. Where ever the light weight is significantly used, magnesium alloys are used in those applications.
Questions:
