Brass is any alloy of copper and zinc; the proportions of zinc and copper can be varied to create a range of brasses with varying properties. An alloy is a Solid solution or Homogeneous mixture of two or more elements, at least one of which is a Metal, which itself has Copper (ˈkɒpɚ is a Chemical element with the symbol Cu (cuprum and Atomic number 29 Zinc (ˈzɪŋk from Zink is a Metallic Chemical element with the symbol Zn and Atomic number 30 ^[1] In comparison, bronze is principally an alloy of copper and tin. Bronze is any of a broad range of Copper alloys, usually with Tin as the main additive but sometimes with other elements such as Phosphorus Tin is a Chemical element with the symbol Sn (stannum and Atomic number 50 ^[2] Despite this distinction, some types of brasses are called bronzes. Brass is a substitutional alloy. An alloy is a Solid solution or Homogeneous mixture of two or more elements, at least one of which is a Metal, which itself has It is used for decoration for its bright gold-like appearance; for applications where low friction is required such as locks, gears, bearings, ammunition, and valves; for plumbing and electrical applications; and extensively in musical instruments such as horns and bells for its acoustic properties. Friction is the Force resisting the relative motion of two Surfaces in contact or a surface in contact with a fluid (e A brass instrument is a Musical instrument whose tone is produced by vibration of the lips as the player blows into a tubular Resonator.

Decorative bolt made in solid brass.

A decorative brass paperweight, left, along with zinc and copper samples.

Brass has a muted yellow color, somewhat similar to gold. Gold (ˈɡoʊld is a Chemical element with the symbol Au (from its Latin name aurum) and Atomic number 79 It is relatively resistant to tarnishing, and is often used as decoration and for coins. Tarnish is a layer of Corrosion that develops over Copper, Brass, Silver, Aluminum as well as a degree of semi-reactive metals as In antiquity, polished brass was often used as a mirror.

Brass has likely been known to humans since prehistoric times, even before zinc itself was discovered. It was produced by melting copper together with calamine, a zinc ore. This article is about calamine in mineralogy For calamine used in calamine lotion see Calamine, for other uses of the word see Calamine (disambiguation. An ore is a volume of rock containing components or Minerals in a mode of occurrence that renders it valuable for mining In the German village of Breinigerberg an ancient Roman settlement was discovered where a calamine ore mine existed. Breinigerberg is one of 17 districts and villages belonging to the city of Stolberg (Rhineland, which is one of the major cities in the district of Aachen. During the melting process, the zinc is extracted from the calamine and mixes with the copper. Pure zinc, on the other hand, has too low a boiling point to have been produced by ancient metalworking techniques. The many references to 'brass' appearing throughout the King James Bible are thought to signify another bronze alloy, or copper, rather than the strict modern definition of 'brass'. ^[3]

Properties

The malleability and acoustic properties of brass have made it the metal of choice for brass musical instruments such as the trombone, tuba, trumpet, euphonium, and the French horn. A brass instrument is a Musical instrument whose tone is produced by vibration of the lips as the player blows into a tubular Resonator. A musical instrument is a device constructed or modified for the purpose of making Music. The trombone is a Musical instrument in the brass family Like all brass instruments it is a lip-reed Aerophone: sound is produced when the player’s Mediatubaogg -->The tuba is the largest and lowest pitched Brass instrument. The euphonium is a conical-bore, Baritone -voiced Brass instrument. Even though the saxophone is classified as a woodwind instrument and the harmonica is a free reed aerophone, both are also often made from brass. The saxophone (commonly referred to simply as sax) is a conical- bored transposing Musical instrument considered a member of the Woodwind Types of woodwind instruments See also List of woodwind instruments Single-reed instruments use a reed, which is a thin cut A harmonica is a free reed Wind instrument which is played by blowing air into it or drawing air out by placing lips over individual holes (reed chambers or A free reed aerophone is a Musical instrument where Sound is produced as air flows past a Vibrating reed in a frame In organ pipes designed as "reed" pipes, brass strips are used as the "reeds". A reed pipe (also referred to as a lingual pipe is an Organ pipe that is sounded by a vibrating Brass strip known as a reed.

Brass has higher malleability than copper or zinc. The relatively low melting point of brass (900 to 940°C, depending on composition) and its flow characteristics make it a relatively easy material to cast. By varying the proportions of copper and zinc, the properties of the brass can be changed, allowing hard and soft brasses.

Today almost 90% of all brass alloys are recycled. Because most brass is nonmagnetic, it can be separated from ferrous scrap by passing the scrap near a powerful magnet. Brass scrap is collected and transported to the foundry where it is melted and recast into billets. Billet refers to a cast Semi finished product. It is also referred to as Ingot, particularly for smaller sizes Billets are heated and extruded into the desired form and size.

Aluminum makes brass stronger and more corrosion resistant. Aluminum also causes a highly beneficial hard layer of aluminium oxide (Al₂O₃) to be formed on the surface that is thin, transparent and self healing. Tin has a similar effect and finds its use especially in sea water applications (naval brasses). Combinations of iron, aluminum, silicon and manganese make brass wear and tear resistant. A well known alloy used in the automotive industry is 'LDM C673', where the combination of manganese and silicon leads to a strong and resistant brass.

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. Selective leaching, also called dealloying, demetalification, parting and selective corrosion, is a Corrosion type in some Solid 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.

The copper in brass makes brass germicidal, via the oligodynamic effect. The' oligodynamic effect' (Greek oligos = few dynamis = force was discovered in 1893 by the Swiss KW Nägeli as a toxic effect of metal-ions on living cells For example, brass doorknobs disinfect themselves of many bacteria within eight hours [2]. This effect is important in hospitals, but useful in many contexts.

Brass door hardware is generally lacquered when new, which prevents tarnishing of the metal for a few years when located outside (and indefinitely when located indoors). After this most manufacturers recommend that the lacquer is removed (e. g. with paint stripper) and the items regularly polished to maintain a bright finish. Unlacquered brass weathers more attractively than brass with deteriorated lacquer, even if polishing is not carried out. Freshly polished brass is similar to gold in appearance, but becomes more reddish within days of exposure to the elements. A traditional polish is Brasso. Brasso is one of the most widely-used and well-known Metal polishes in the world

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. Cryogenics is often used incorrectly to refer to Cryonics, cryopreserving humans or animals ^[4]

Season cracking

Brass is susceptible to stress corrosion cracking, especially from ammonia or substances containing or releasing ammonia. Fracture mechanics --> Stress corrosion cracking ( SCC) is the unexpected sudden failure of normally Ductile metals or tough Thermoplastics Ammonia is a compound with the formula N[[hydrogen H3]] It is normally encountered as a Gas with a characteristic pungent Odor 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. The problem of season cracking is known from Brass cartridge failures during the monsoon season in India in the 1920s failures which were caused by attack of the metal by ammonia A cartridge (also known as a "round" packages the Bullet, Gunpowder and primer into a single metallic case precisely made to fit the A rifle is a Firearm designed to be fired from the shoulder with a barrel that has a helical groove or pattern of grooves ("rifling" cut into the barrel walls Ammunition, often referred to as ammo, is a generic term derived from the French language la munition which The Indian Army (Bharatiya Thalsena भारतीय थाल्सेना is one of the armed forces of India and has the responsibility for land-based 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. Residual stresses are stresses that remain after the original cause of the stresses (external forces heat gradient has been removed

The density of brass is approximately 8. 4 g/cm³.

Brass types

• Admiralty brass contains 30% zinc and 1% tin which inhibits dezincification in most environments. Tin is a Chemical element with the symbol Sn (stannum and Atomic number 50 Selective leaching, also called dealloying, demetalification, parting and selective corrosion, is a Corrosion type in some Solid
• 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. Prince's metal or Prince Rupert's metal is a type of alpha- Brass containing 75% Copper and 25% Zinc. They contain only one phase, with face-centered cubic crystal structure. The cubic crystal system (or isometric) is a Crystal system where the Unit cell is in the shape of a Cube. In Mineralogy and Crystallography, a crystal structure is a unique arrangement of Atoms in a Crystal.
• Alpha-beta brass (Muntz metal), also called duplex brass, is 35-45% zinc and is suited for hot working. Muntz Metal is a form of alpha-beta Brass with about 60% Copper, 40% Zinc and a trace of iron It contains both α and β' phase; the β'-phase is body-centered cubic and is harder and stronger than α. The cubic crystal system (or isometric) is a Crystal system where the Unit cell is in the shape of a Cube. Alpha-beta brasses are usually worked hot.
• Aluminium brass contains aluminium, which improves its corrosion resistance. Used in Euro coins (Nordic gold). Linguistic Nordic gold is the Alloy from which the middle three denominations of Euro coins, 50 cent 20 cent and 10 cent Coins are made
• Arsenical brass contains an addition of arsenic and frequently aluminium and is used for boiler fireboxes. Arsenic (ˈɑrsənɪk is a Chemical element that has the symbol As and Atomic number of 33 A boiler is a closed vessel in which Water or other Fluid is heated
• 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. Gilding metal is a Copper Alloy, comprising 95% copper and 5% Zinc. Ammunition, often referred to as ammo, is a generic term derived from the French language la munition which
• High brass, contains 65% copper and 35% zinc, has a high tensile strength and is used for springs, screws, rivets. A spring is a flexible elastic object used to store mechanical Energy. A screw is a shaft with a helical groove or thread formed on its surface and provision at one end to turn the screw A rivet is a mechanical Fastener. Before it is installed it consists of a smooth cylindrical shaft with a head on one end
• Leaded brass is an alpha-beta brass with an addition of lead. Characteristics Lead has a dull luster and is a dense, Ductile, very soft highly 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. A bellows is a device for delivering pressurized Air in a controlled quantity to a controlled location
• 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. Gunmetal is a type of Bronze &ndash an Alloy of Copper, Tin, and Zinc.
• 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. Copper alloys are Alloys with Copper as their principal component Orichalcum is a legendary Metal mentioned in several ancient writings most notably the story of Atlantis as recounted in the Critias dialogue Calamine brass is Brass produced by a particular Alloying technique using calamine, a zinc Ore, rather than metallic zinc Gilding metal is a Copper Alloy, comprising 95% copper and 5% Zinc. Corinthian bronze, also called Corinthian brass or æs Corinthiacum, was a highly valuable Metal Alloy in Classical antiquity. Pinchbeck is a form of Brass, an Alloy of Copper and Zinc mixed in proportions so that it 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