Alcoa 2000 Annual Report Download - page 69

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Glossary
Alloy A substance with metallic
properties, composed of two
or more chemical elements of
whichatleastoneisametal.More
specifically, aluminum plus one
or more other elements, produced
to have certain specific, desirable
characteristics.
Alumina Aluminum oxide pro-
duced from bauxite by an intricate
chemical process. It is a white
powdery material that looks like
granulated sugar. Alumina is an
intermediate step in the production
of aluminum from bauxite and is
also a valuable chemical on its own.
Aluminum foil A flat-rolled
product, rectangular in cross
section, of thickness from 0.006⬙
to 0.00025⬙.
Aluminum plate A flat-rolled
product, rectangular in cross
section, of thickness not less than
0.250⬙andwithshearedorsawed
edges.
Aluminum sheet Arolled
product, flat or coiled, rectangular
in cross section, with thickness
less than 0.250⬙but not less than
0.006 ⬙and with slit, sheared or
sawed edges.
Aluminum SpaceFrame姠An
integrated structure of aluminum
castings and extruded parts that
forms the primary body frame
of a new generation of automobiles.
Anodizing An electrochemical
process for applying a protective or
decorative coating to metal surfaces.
Bauxite An ore from which
alumina is extracted and from
which aluminum is eventually
smelted. Bauxite usually contains
at least 45% alumina. About four
pounds of bauxite are required
to produce one pound of aluminum.
Casting The process of forming
molten metal into a particular
shape by pouring it into a mold
and letting it harden.
Continuous casting A means of
casting aluminum in which an ingot,
billet, tube or other shape is contin-
uously solidified and withdrawn
while the molten metal is being
poured, so that its length is not
determined by mold dimensions.
Engineered product Abasic
aluminum fabricated product that
has been mechanically altered
to create special properties for
specific purposes; forgings and
extrusions are examples of
engineered products.
Extrusion The process of shaping
material by forcing it to flow
through a shaped opening in a die.
Fabricate Toworkamaterialinto
a finished state by machining,
forming or joining.
Flat-rolled products Aluminum
plate, sheet or foil products made
by passing ingot through pairs
of rolls. By moving the rolls closer
together and passing the ingot
between them, the thickness is
reduced and the length is increased.
Forging Ametalpartworkedto
predetermined shape by one or
more processes such as hammering,
pressing or rolling.
Hydrate An aluminum oxide with
three molecules of chemically
combined water.
Ingot Acastformsuitablefor
remelting or fabricating. An ingot
may take many forms: some may
be 30 feet long and weigh 15 tons;
others are notched or specially
shaped for stacking and handling.
London Metal Exchange
(LME)
The international trading body
that facilitates the worldwide open
market buying and selling of metals.
Magnesium A light, silvery,
moderately hard metallic element
used in processing metals and
chemicals, and in alloying aluminum
to give it desired metallurgical
properties.
Metric ton (mt) Aunitofmassand
weight equal to 1,000 kilograms,
or 2,204.6 pounds.
Micromill Alcoa Micromill
technology uses fully continuous
casting and rolling processes to
produce aluminum sheet with
reduced capital investment, lower
operating costs, and– for some
products – superior metallurgical
properties.
Mill products Metal that has been
fabricated into an intermediate form
before being made into a finished
product. The most common fabri-
cating processes for aluminum are
rolling, extruding, forging and
casting. Example: aluminum sheet,
a mill product, is used to make
beverage cans, a finished product.
Pot In aluminum production:
the electrolytic reduction cell,
commonly called a ‘‘pot,’’ in
which alumina dissolved in molten
cryolite is reduced to metallic alu-
minum. A series of cells connected
electrically is called a potline.
Smelt To fuse or melt ore in
order to extract or refine the metal
it contains.