Magnalium is an

aluminium Aluminium (or aluminum in North American English) is a chemical element; it has chemical symbol, symbol Al and atomic number 13. It has a density lower than that of other common metals, about one-third that of steel. Aluminium has ...

alloy An alloy is a mixture of chemical elements of which in most cases at least one is a metal, metallic element, although it is also sometimes used for mixtures of elements; herein only metallic alloys are described. Metallic alloys often have prop ...

with 50%

magnesium Magnesium is a chemical element; it has Symbol (chemistry), 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 ...

and 50%

aluminum Aluminium (or aluminum in North American English) is a chemical element; it has chemical symbol, symbol Al and atomic number 13. It has a density lower than that of other common metals, about one-third that of steel. Aluminium 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 ratio of a substance's mass to its volume. The symbol most often used for density is ''ρ'' (the lower case Greek letter rho), although the Latin letter ''D'' (or ''d'') can also be u ...

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

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 and automobile parts. It is also used for making balance beams and other components of light instruments.

Pyrotechnics

Alloys; which are generally not true alloys but intermetallic compounds; with about 50% magnesium are brittle and corrode easily, which makes them unsuitable for most engineering uses. These compounds are flammable when powdered, are more resistant to corrosion than pure magnesium, and are generally more reactive than pure aluminium; they are used in

pyrotechnics Pyrotechnics is the science and craft of creating fireworks, but also includes safety matches, oxygen candles, Pyrotechnic fastener, explosive bolts (and other fasteners), parts of automotive airbags, as well as gas-pressure blasting in mining, q ...

as a metal fuel for colored flames, to produce sparks in some glitter and streamer stars, and as a more consistent replacement for separate magnesium and aluminum powders in crackling microstars ( dragon eggs). Magnalium powder also burns with a crackling sound if burnt by itself. It is somewhat less reactive than magnesium in most cases, showing no reaction with sulfur in particular, but is nearly as reactive as magnesium with antimony trisulfide (producing the extremely poisonous and flammable

Hydrogen sulfide Hydrogen sulfide is a chemical compound with the formula . It is a colorless chalcogen-hydride gas, and is toxic, corrosive, and flammable. Trace amounts in ambient atmosphere have a characteristic foul odor of rotten eggs. Swedish chemist ...

gas) and more dangerously reactive with nitrates, slowly reacting to produce ammonia gas where magnesium only reacts slowly to produce inert products. In some cases the normally faster-reacting magnesium component of magnalium serves to slow down a reaction due to its higher reactivity in a composition. This occurs in dragon eggs, where slower oxidation of magnesium by Lead tetraoxide () allows time for the formed Lead monoxide () gas to build up without reacting with the aluminum portion, so when the magnesium is finally consumed the aluminum reaction occurs rapidly enough to produce an explosion. If too much magnesium is present in the alloy (or added to the mix), it will burn continuously but not produce the desired effect. Similarly too little magnesium will prevent enough vapor from building up to react rapidly and the aluminum will simply burn.

References

External links

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

Properties

Uses

Pyrotechnics

See also

References

External links