Aluminium or aluminum
(US: /əˈluːmɨnəm/ (
listen) ə-LOO-mi-nəm) is a silvery white member of the boron group
of chemical elements. It has the symbol Al and
its atomic
number is 13. It is not soluble in water under normal circumstances.
Aluminium is the most abundant metal in the Earth's crust,
and the third most abundant element, 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 a free metal. Instead, it is found combined in
over 270 different minerals. The chief source of aluminium is bauxite ore.
Detailed description:
listen) ə-LOO-mi-nəm) is a silvery white member of the boron group
of chemical elements. It has the symbol Al and
its atomic
number is 13. It is not soluble in water under normal circumstances.
Aluminium is the most abundant metal in the Earth's crust,
and the third most abundant element, 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 a free metal. Instead, it is found combined in
over 270 different minerals. The chief source of aluminium is bauxite ore.
Aluminium
is remarkable for the metal's low density and for its ability to resist corrosion due
to the phenomenon of passivation. Structural components made from aluminium
and its alloys are vital to the aerospace
industry and are very important in other areas of transportation
and building. Its reactive nature makes it useful as a catalyst or
additive in chemical mixtures, including ammonium
nitrate explosives,
to enhance blast power.
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Characteristics
Aluminium
is a soft, durable, lightweight, ductile and malleable metal with appearance
ranging from silvery to dull gray, depending on the surface roughness.
Aluminium is nonmagnetic and nonsparking. It is also insoluble in alcohol,
though it can be soluble in water in certain forms. The yield strength of pure aluminium is 7–11 MPa,
while aluminium alloys have yield strengths ranging from
200 MPa to 600 MPa.[7]
Aluminium has about one-third the density and stiffness
of steel. It is
easily machined,
cast, drawn and extruded.
Corrosion
resistance can be 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. This corrosion resistance is also often greatly reduced
when many aqueous salts are present, particularly in the presence of dissimilar
metals.
Aluminium
atoms are arranged in a face-centered cubic (fcc) structure. Aluminium
has a stacking-fault energy of approximately 200
mJ/m2.
Aluminium
is one of the few metals that 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 3,000–10,000 nm (far IR) regions; in the 400–700 nm visible range it is
slightly outperformed by tin
and silver and
in the 700–3000 (near IR) by silver, gold, and copper.
Aluminium
is a good thermal and electrical conductor, having 62% the
conductivity of copper.
Aluminium is capable of being a superconductor,
with a superconducting critical temperature of 1.2 kelvins and a
critical magnetic field of about 100 gauss
(10 milliteslas).
Price
$1.7/kg
For more information:
mobile: +2348039721941
contact person: emeaba uche
e-mail: emeabau@yahoo.com
website: www.franchiseminerals.com
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