Magnalium is an

aluminium Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. I ...

alloy An alloy is a mixture of chemical elements of which at least one is a metal. Unlike chemical compounds with metallic bases, an alloy will retain all the properties of a metal in the resulting material, such as electrical conductivity, ductility, ...

with 5%

magnesium Magnesium is a chemical element with the symbol Mg and atomic number 12. It is a shiny gray metal having a low density, low melting point and high chemical reactivity. Like the other alkaline earth metals (group 2 of the periodic ta ...

and 95%

aluminum Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. It has ...

Properties

Alloys with small amounts of magnesium (about 5%) exhibit greater strength, greater

corrosion Corrosion is a natural process that converts a refined metal into a more chemically stable oxide. It is the gradual deterioration of materials (usually a metal) by chemical or electrochemical reaction with their environment. Corrosion engine ...

resistance, and lower

density Density (volumetric mass density or specific mass) is the substance's mass per unit of volume. The symbol most often used for density is ''ρ'' (the lower case Greek letter rho), although the Latin letter ''D'' can also be used. Mathematical ...

than pure aluminium. Such alloys are also more workable and easier to weld than pure aluminium.magnalium — Infoplease.com
/ref> Alloys with high amounts of magnesium (around 50%) are brittle and more susceptible to corrosion than aluminium.

Uses

Although they are generally more expensive than aluminium, the high strength, low density, and greater workability of alloys with low amounts of magnesium leads to their use in

aircraft An aircraft is a vehicle that is able to fly by gaining support from the air. It counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines ...

and

automobile A car or automobile is a motor vehicle with Wheel, wheels. Most definitions of ''cars'' say that they run primarily on roads, Car seat, seat one to eight people, have four wheels, and mainly transport private transport#Personal transport, pe ...

parts. Alloys with about 50% magnesium are brittle and

corrode Corrosion is a natural process that converts a refined metal into a more chemically stable oxide. It is the gradual deterioration of materials (usually a metal) by chemical or electrochemical reaction with their environment. Corrosion engin ...

easily, which makes them unsuitable for most engineering uses. However, these alloys are flammable when powdered, are more resistant to corrosion than pure magnesium, and are more reactive than pure aluminium and are therefore used in

pyrotechnics Pyrotechnics is the science and craft of creating such things as fireworks, safety matches, oxygen candles, explosive bolts and other fasteners, parts of automotive airbags, as well as gas-pressure blasting in mining, quarrying, and demolition. ...

as a metal

fuel A fuel is any material that can be made to react with other substances so that it releases energy as thermal energy or to be used for work. The concept was originally applied solely to those materials capable of releasing chemical energy but ...

and to produce sparks. Due to the high reactivity, magnalium burns comparably hot and forms bright yellowish white sparks. Magnalium powder also burns with a crackling sound if burnt by itself, and provides a good compromise between the reactivity of magnesium and the stability of aluminium. Another benefit for pyrotechnics is the brittleness of the alloy, as mentioned before. It is easily broken with a hammer and then ground in a coffee grinder to usable powder. It will grind in a

ball mill A ball mill is a type of grinder used to grind or blend materials for use in mineral dressing processes, paints, pyrotechnics, ceramics, and selective laser sintering. It works on the principle of impact and attrition: size reduction is done ...

into a fine powder in a matter of hours, as opposed to a matter of days with aluminium powder. It is much more powerful than aluminium powder (when compared at similar mesh size) and similar precautions should be taken as per magnesium. These include dangers of moisture and incompatibility with other compounds (boric acid and ammonium compounds). It is also used for making balance beams and other components of light instruments.

References

External links

Making Magnalium
* http://www.thegreenman.me.uk/pro/magnalium.html Aluminium–magnesium alloys Aluminium alloys Magnesium alloys Pyrotechnic fuels {{Pyrotechnics-stub

Properties

Uses

See also

References

External links