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 Brass alloys
Brasses are alloys that are a raw combination of Copper and Zinc. It
has a yellow colour, somewhat similar to gold. It is relatively
resistant to tarnishing, and is often used as decoration. These have
high corrosion resistance and high tensile strength and also suited to
be fabricated by hot forging. Certain brasses can corrode in various
environments. Aluminium makes brass stronger and more corrosion
resistant.
Free machining grades of brass set the standard for machining by
which other metals are compared. Brasses are divided into two classes.
The alpha alloys, with less than 37% Zinc and the alpha/beta alloys
with 37-45% zinc. Alpha alloys are flexible and can be cold worked.
Alpha/beta or duplex alloys have limited cold ductility and are harder
and stronger. By varying the proportions of copper and zinc, the
properties of the brass can be changed, allowing hard and soft brasses.
The relatively low melting point (900-940 degrees C depending on
composition) of brass and its flow characteristics make it a relatively
easy material to cast.
Brasses are used in applications such as blanking, coining,
drawing, piercing, springs, fire extinguishers, jewelry, radiator
cores, lamp fixtures, ammunition, flexible hose, and the base for gold
plate. The cast brasses are used in applications such as plumbing
fixtures, fittings and low-pressure valves, gears, bearings, decorative
hardware and architectural trim. Brass alloys are very useful for
architectural applications, high strength components, valves, valve
stems, fittings, and marine fittings.
The malleability and acoustic properties of brass have made it
the metal of choice for brass musical instruments such as the trumpet,
tuba, trombone, saxophone, harmonica and euphonium. Brass has higher
malleability than copper or zinc.
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