brass

1 an alloy of copper and zinc

2 a wind instrument that consists of a brass tube (usually of variable length) blown by means of a cup-shaped or funnel-shaped mouthpiece

3 the persons (or committees or departments etc.) who make up a body for the purpose of administering something; "he claims that the present administration is corrupt"; "the governance of an association is responsible to its members"; "he quickly became recognized as a member of the establishment" [syn: administration, governance, governing body, establishment, organization, organisation]

4 impudent aggressiveness; "I couldn't believe her boldness"; "he had the effrontery to question my honesty" [syn: boldness, nerve, face, cheek]

5 an ornament or utensil made of brass

6 the section of a band or orchestra that plays brass instruments [syn: brass section]

7 a memorial made of brass [syn: memorial tablet, plaque]

English

Pronunciation

• a US /bɹɑs/, /brA:s/
• a UK /bɹæs/|/bɹɑs/, /br

Properties

Applications

The so called dezincification resistant (DZR) brasses, like alloy 'LDM G563' (known for its brand name 'Enkotal'), are used where there is a large corrosion risk and where normal brasses do not meet the standards. Applications with high water temperatures, chlorides present or deviating water qualities (soft water) play a role. DZR-brass is excellent in water boiler systems. This brass alloy must be produced with great care, with special attention placed on a balanced composition and proper production temperatures and parameters to avoid long-term failures. Drunen, Netherlands, has the only active production facility which makes these high grade brass alloys.

Brass was used to make fan blades, fan cages and motor bearings in many antique fans that date before the 1930s. Brass can be used for fixings for use in cryogenic systems, however its use is not limited to this.

Season cracking

Brass is susceptible to stress corrosion cracking, especially from ammonia or substances containing or releasing ammonia. The problem is sometimes known as season cracking after it was first discovered in brass cartridge cases used for rifle ammunition during the 1920s in the Indian Army. Brittle cracks could cause serious accidents if the case was too weak to resist the charge when the rifle was fired. The problem was caused by high residual stresses from cold forming of the cases during manufacture, and was cured by annealing the cases.

Brass types

• Admiralty brass contains 30% zinc and 1% tin which inhibits dezincification in most environments.
• Alpha brasses (Prince's metal), with less than 35% zinc, are malleable, can be worked cold, and are used in pressing, forging, or similar applications. They contain only one phase, with face-centered cubic crystal structure.
• Alpha-beta brass (Muntz metal), also called duplex brass, is 35-45% zinc and is suited for hot working. It contains both α and β' phase; the β'-phase is body-centered cubic and is harder and stronger than α. Alpha-beta brasses are usually worked hot.
• Aluminium brass contains aluminium, which improves its corrosion resistance. Used in Euro coins (Nordic gold).
• Arsenical brass contains an addition of arsenic and frequently aluminium and is used for boiler fireboxes.
• Beta brasses, with 45-50% zinc content, can only be worked hot, and are harder, stronger, and suitable for casting.
• Cartridge brass is a 30% zinc brass with good cold working properties.
• Common brass, or rivet brass, is a 37% zinc brass, cheap and standard for cold working.
• DZR brass is Dezincification resistant Brass with a small percentage of Arsenic.
• Gilding metal is the softest type of brass commonly available. An alloy of 95% copper and 5% zinc, gilding metal is typically used for ammunition components.
• High brass, contains 65% copper and 35% zinc, has a high tensile strength and is used for springs, screws, rivets.
• Leaded brass is an alpha-beta brass with an addition of lead. It has excellent machinability.
• Low brass is a copper-zinc alloy containing 20% zinc with a light golden color, excellent ductility and is used for flexible metal hoses and metal bellows.
• Naval brass, similar to admiralty brass, is a 40% zinc brass and 1% tin.
• Red brass, while not technically brass, is an American term for CuZnSn alloy known as gunmetal.
• White brass contains more than 50% zinc and is too brittle for general use.
• Yellow brass is an American term for 33% zinc brass.

See also

• Copper alloys
• Orichalcum
• Calamine brass — brass alloy and manufacturing process from discovery until the late 18th century
• Gilding metal; the softest form of brass commonly available
• Corinthian brass — an alloy of gold, silver and copper, known to antiquity
• Pinchbeck — a brass that closely resembles gold in appearance.
• Bronze — an alloy of copper with tin and optionally zinc, silicon, nickel and other metals
• Cupronickel — an alloy of copper with nickel
• Tombac — an alloy of copper with zinc
• Brass instrument — a musical instrument usually made of brass
• Brass rubbing — reproduction of brasses, commemorative plates laid down in British and European churches from the 13th Century onwards'''
• Brass bed — history of the usage of brass in beds and bedframes
• Latten — early brass alloys (Calamine brasses)
• Season cracking — attack of brass by ammonia

External links

• National Pollutant Inventory - Copper and compounds fact sheet
• The Copper Development Association also maintains a web site dedicated to brass

References