|
Aluminum
more...
Home
Animals
Arcade, Jukeboxes & Pinball
Autographs
Banks, Registers & Vending
Barware
Bottles & Insulators
Breweriana, Beer
Casino
Clocks
Furniture, Appliances & Fans
Housewares & Kitchenware
Knives, Swords & Blades
Lamps, Lighting
Linens, Fabric & Textiles
Metalware
Aluminum
Brass
Bronze
Cast Iron
Chrome
Copper
Other Metalware
Pewter
Silverplate
Sterling Silver
Tin
Militaria
Pens & Writing Instruments
Pez, Keychains, Promo...
Aluminium (IPA: /ˌæljʊˈmɪniəm/, /ˌæljəˈmɪniəm/) or aluminum (IPA: /əˈluːmɪnəm/, see "spelling" below) is a silvery white and ductile member of the poor metal group of chemical elements. It has the symbol Al; its atomic number is 13. Aluminium is the most abundant metal in the Earth's crust, and the third most abundant element overall, after oxygen and silicon. It makes up about 8% by weight of the Earth’s solid surface. Aluminium is too reactive chemically to occur in nature as the free metal. Instead, it is found combined in over 270 different minerals . The chief source of aluminium is bauxite ore. Aluminium is remarkable for its ability to resist corrosion (due to the phenomenon of passivation) and its light weight. Structural components made from aluminium and its alloys are vital to the aerospace industry and very important in other areas of transportation and building.
Properties
Aluminium is a soft, lightweight, malleable metal with appearance ranging from silvery to dull gray, depending on the surface roughness. Aluminium is nontoxic, nonmagnetic, and nonsparking. The yield strength of pure aluminium is 7–11 MPa, while aluminium alloys have yield strengths ranging from 200 MPa to 600 MPa. Aluminium has about one-third the density and stiffness of steel. It is ductile, and easily machined, cast, and extruded.
Corrosion resistance is excellent due to a thin surface layer of aluminium oxide that forms when the metal is exposed to air, effectively preventing further oxidation. The strongest aluminium alloys are less corrosion resistant due to galvanic reactions with alloyed copper.
Aluminium atoms are arranged in an FCC structure. Aluminium has a high stacking-fault energy of approximately 200 mJ/m².
Aluminium is one of the few metals which retain full silvery reflectance in finely powdered form, making it an important component of silver paints. Aluminium mirror finish has the highest reflectance of any metal in the 200–400 nm (UV) and the 3000–10000 nm (far IR) regions, while in the 400–700 nm visible range it is slightly outdone by silver and in the 700–3000 (near IR) by silver, gold, and copper.
Read more at Wikipedia.org
|
|