Download Gold, Aluminium and their Alloys

Gold, Aluminium and their Alloys
By Duncan & Jamie
Gold
• Gold easily creates alloys with many other
metals.
• These alloys can be produced to improve the
hardness and other properties, to control
melting point or to create exotic colours.
Gold Alloys
• Coloured gold alloys are just as "real" as their
golden coloured counterparts. Pure gold is
generally too soft to be used for jewelry, so other
metals are nearly always added to it, no matter
which colour of gold is being prepped for
jewellery making.
• Chances are the ring is marked 18K, 14K, or 10K
to indicate how much pure gold is present in the
mix. The K stands for karat, the system used to
state how much pure gold is found in an item.
Gold Karat Markings
• 24K gold is pure gold.
• 18K gold contains 18 parts gold and 6 parts of another
metal(s), making it 75% gold.
• 14K gold contains 14 parts gold and 10 parts of another
metal(s), making it 58.3% gold.
• 12K gold contains 12 parts gold and 12 parts of another
metal(s), making it 50% gold.
• 10K gold contains 10 parts gold and 14 parts another
metal(s), making it 41.7% gold. 10K gold is the minimum
karat designation that can still be called gold in the US.
• Even 18K gold, with its 6 parts of another metal, gives
jewelers the opportunity to play around with color.
Gold Alloys uses
• Gold alloys are used for fillings, crowns,
bridges and orthodontic appliances.
Aluminium
• Aluminium can be added to alloys as well. For
example the addition of scandium to
aluminium stops the growth that occurs when
aluminium is welded.
Uses
• Some items of sports equipment, which rely
on high performance materials, have been
made with scandium-aluminium alloys,
including baseball bats, lacrosse sticks, as well
as bicycle frames and components. U.S. gun
maker Smith & Wesson produces revolvers
with frames composed of scandium alloy and
cylinders of titanium.