Written by Aluminum Anodizing.
As mentioned earlier aluminum powder and pastes find wide application in paints, lacquers and other coatings. Precautions in formulation, mixing and use are necessary in order to produce leafing of the pigment but the species requirement are now rather well understood and offer no great difficulties in most applications. Aluminum paints are used on structural metal and steel such as factories, bridges and towers; the high reflectivity of such paints has long been utilized on oil storage tanks. Aluminum pigment is resistant to discoloration by hydrogen sulfide and to industrial gases and smokes in general, which make which makes it especially valuable in paint for interior as well as exterior use on concrete, brick, wood, plaster, and metal in factories, mines, and also on farms and agriculture equipments. It is also used in special paints resistant to moderately high temperatures for use on boilers, motors and stacks. Aluminum paint has been recommended and uses as a primer for exterior wood of houses and as a sealer over materials which bleed into and discolor finish coat paints. Aluminum pigments are used in protective and decorative lacquers and in popular metallic, polychromatic or chromatic finish is obtained by using non-leafing type of aluminum finish which simulates a hammered metal appearance. Aluminum powder and pastes are also used in inks, and paper coating, lithography, in bituminous coatings for roofs and as a filler in rubber.
Another important use of aluminum powder is in pyrotechnics. Atomized aluminum powder is used in the manufacture of fireworks and explosives. Aluminum powder is used in the manufacture of Ziegler's catalyst (a mixture of triethyl aluminum and titanium tetrachloride) used in the polymerization reaction of ethylene and propylene. Other applications of aluminum powder include its use in thermit welding: in metallurgy for the reduction of oxide of chromium, manganese, titanium, etc., in steel making to prevent the oxidation and aid uniform heating of molten metal; as a propellant ingredient in rocket fuel; in vacuum metallizing of gloss sheet and plastic products: in manufacture of break lining; in special types of welding fluxes; and in the manufacture of sintered aluminum powder which is used for jet deflectors in missiles and as structural material in nuclear reactors.