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Lead Alloys |
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Lead
is very soft and ductile and is normally used
commercially as lead alloys. Antimony, tin, arsenic, and
calcium are the most common alloying elements. Antimony
generally is used to give greater hardness and strength,
as in storage battery grids, sheet, pipe, and castings.
Antimony contents of lead-antimony alloys can range from
0.5 to 25%, but they are usually 2 to 5%.
Lead-Calcium Alloys have
replaced lead-antimony alloys in a number of
applications, in particular, storage battery grids and
casting applications. These alloys contain 0.03 to 0.15%
Ca. More recently, aluminum has been added to
calcium-lead and calcium-tin-lead alloys as a stabilizer
for calcium. Adding tin to lead or lead alloys increases
hardness and strength, but lead-tin alloys are more
commonly used for their good melting, casting, and
wetting properties, as in type metals and solders. Tin
gives the alloy the ability to wet and bond with metals
such as steel and copper; unalloyed lead has poor
wetting characteristics. Tin combined with lead and
bismuth or cadmium forms the principal ingredient of
many low-melting alloys.
Arsenical lead (UNS L50310) is used
for cable sheathing. Arsenic is often used to harden
lead-antimony alloys and is essential to the production
of round dropped shot. |
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