Product Code Database
Magnalium is an alloy of aluminium and magnesium.
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 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 aluminium 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 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 aluminium portion, so when the magnesium is finally consumed the aluminium 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 aluminium will simply burn.
|
|
