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Engineering
Materials - Nonferrous
Metals - Gold, Silver, Platinum
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Materials: Non-Ferrous Metals
Precious
Metals
- Gold is an extremely
inert, soft, ductile metal, that undergoes
very little work hardening. A gram of
pure gold can be worked into leaf covering
6 ft^2 and only 0.0000033 in. thick. It
is used chiefly for linings or electrodeposits
and is often alloyed with other metals
such as copper or nickel to increase strength
or hardness.
- Silver is a very
malleable, ductile, and corrosion resistant
metal that has the highest thermal and
electrical conductivity of all metals
and is the least costly of all the precious
metals. Alloyed with copper, and sometimes
with zinc, silver is also used in high-melting
temperature solders.
- Platinum is an
extremely malleable, ductile, and corrosion
resistant silver-white metal. When heated
to redness, it softens and is easily worked.
It is nearly nonoxidizable and is soluble
only in liquids that generate free chlorine
such as aqua regia. Because platinum is
inert and stable, even at high temperatures,
the metal is used for high-temperature
handling of high-purity chemicals and
laboratory materials. Other applications
include electrical contacts, resistance
wire, thermocouples, and standard weights.
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