Phosphor bronze is a member of the family of copper alloys. It is composed of

copper Copper is a chemical element with the symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pink ...

that is

alloyed An alloy is a mixture of chemical elements of which at least one is a metal. Unlike chemical compounds with metallic bases, an alloy will retain all the properties of a metal in the resulting material, such as electrical conductivity, ductility, ...

with 0.5–11% of tin and 0.01–0.35%

phosphorus Phosphorus is a chemical element with the symbol P and atomic number 15. Elemental phosphorus exists in two major forms, white phosphorus and red phosphorus, but because it is highly reactive, phosphorus is never found as a free element on Ea ...

, and may contain other elements to confer specific properties (e.g.

lead Lead is a chemical element with the symbol Pb (from the Latin ) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point. When freshly cut, ...

at 0.5–3.0% to form free-machining phosphor bronze). Alloyed tin increases the corrosion resistance and strength of copper, while phosphorus increases its wear resistance and stiffness. These alloys are notable for their

toughness In materials science and metallurgy, toughness is the ability of a material to absorb energy and plastically deform without fracturing.strength, low

coefficient of friction Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. There are several types of friction: *Dry friction is a force that opposes the relative lateral motion of t ...

, and fine

grain A grain is a small, hard, dry fruit ( caryopsis) – with or without an attached hull layer – harvested for human or animal consumption. A grain crop is a grain-producing plant. The two main types of commercial grain crops are cereals and legum ...

. The phosphorus reduces the

viscosity The viscosity of a fluid is a measure of its resistance to deformation at a given rate. For liquids, it corresponds to the informal concept of "thickness": for example, syrup has a higher viscosity than water. Viscosity quantifies the int ...

of the molten alloy, which makes it easier and cleaner to

cast Cast may refer to: Music * Cast (band), an English alternative rock band * Cast (Mexican band), a progressive Mexican rock band * The Cast, a Scottish musical duo: Mairi Campbell and Dave Francis * ''Cast'', a 2012 album by Trespassers William ...

and reduces

grain boundaries In materials science, a grain boundary is the interface between two grains, or crystallites, in a polycrystalline material. Grain boundaries are two-dimensional defects in the crystal structure, and tend to decrease the electrical and therma ...

between crystallites. It was originally formulated by the Belgian

Georges Montefiore-Levi Georges Montefiore-Levi (18 February 1832 – 24 April 1906) was a Belgian politician, industrialist and inventor of Jewish extraction who created the first phosphorus bronze. Early life He was born in Streatham, South London. His father, Isa ...

Industrial uses

Phosphor bronze is used for springs, bolts, bushings and bearings, electrical switches with moving or sliding parts, dental bridges, the reed component of organ pipes and various other products or assemblies where resistance to fatigue, wear, and corrosion are required (e.g., ship's

propeller A propeller (colloquially often called a screw if on a ship or an airscrew if on an aircraft) is a device with a rotating hub and radiating blades that are set at a pitch to form a helical spiral which, when rotated, exerts linear thrust upon ...

s in a

marine Marine is an adjective meaning of or pertaining to the sea or ocean. Marine or marines may refer to: Ocean * Maritime (disambiguation) * Marine art * Marine biology * Marine debris * Marine habitats * Marine life * Marine pollution Military ...

environment). Phosphor bronze comes in a wide array of standard alloys, including nonferrous spring alloys, free-machining phosphor bronze and bearing bronze. The combination of good physical properties, fair electrical conductivity, and moderate cost make phosphor bronze, available in standard round, square, flat, and special format wire desirable for many springs, electrical contacts, and a wide variety of wire forms where the desired properties do not require the use of more expensive

beryllium copper Beryllium copper (BeCu), also known as copper beryllium (CuBe), beryllium bronze, and spring copper, is a copper alloy with 0.5–3% beryllium but can contain other elements as well. Beryllium copper combines high strength with non-magnetic and ...

. Phosphor bronze (94.8%

, 5% tin, 0.2%

) is also used in

cryogenics In physics, cryogenics is the production and behaviour of materials at very low temperatures. The 13th IIR International Congress of Refrigeration (held in Washington DC in 1971) endorsed a universal definition of “cryogenics” and “c ...

. In this application, its combination of fair

electrical conductivity Electrical resistivity (also called specific electrical resistance or volume resistivity) is a fundamental property of a material that measures how strongly it resists electric current. A low resistivity indicates a material that readily allows ...

and low

thermal conductivity The thermal conductivity of a material is a measure of its ability to conduct heat. It is commonly denoted by k, \lambda, or \kappa. Heat transfer occurs at a lower rate in materials of low thermal conductivity than in materials of high thermal ...

allows the making of electrical connections to devices at ultra low temperatures without adding excessive heat.

Spent nuclear fuel overpack

Oxygen-free copper Oxygen-free copper (OFC) or oxygen-free high thermal conductivity (OFHC) copper is a group of wrought high-conductivity copper alloys that have been electrolytically refined to reduce the level of oxygen to 0.001% or below. Specification Ox ...

can be alloyed with

( CuOFP alloy) to better withstand oxidizing conditions. This alloy has application as thick corrosion-resistant overpack for

spent nuclear fuel Spent nuclear fuel, occasionally called used nuclear fuel, is nuclear fuel that has been irradiated in a nuclear reactor (usually at a nuclear power plant). It is no longer useful in sustaining a nuclear reaction in an ordinary thermal reactor and ...

disposal in deep crystalline rocks.

UNIVAC computer

Magnetic tape was first used to record computer data in 1951 on the Eckert- Mauchly

UNIVAC I The UNIVAC I (Universal Automatic Computer I) was the first general-purpose electronic digital computer design for business application produced in the United States. It was designed principally by J. Presper Eckert and John Mauchly, the inven ...

. The UNISERVO drive recording medium was a thin metal strip of wide

nickel Nickel is a chemical element with symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel is a hard and ductile transition metal. Pure nickel is chemically reactive but large pieces are slow t ...

-plated phosphor bronze. Recording density was 128 characters per inch (198 micrometre/character) on eight tracks at a linear speed of , yielding a data rate of 12,800 characters per second. Of the eight tracks, six were data, one was a parity track, and one was a clock, or timing track. Making allowance for the empty space between tape blocks, the actual transfer rate was around 7,200 characters per second. A small reel of mylar tape provided separation from the metal tape and the read/write head.

Musical instruments

Phosphor bronze is preferred over

brass Brass is an alloy of copper (Cu) and zinc (Zn), in proportions which can be varied to achieve different mechanical, electrical, and chemical properties. It is a substitutional alloy: atoms of the two constituents may replace each other wi ...

for

cymbal A cymbal is a common percussion instrument. Often used in pairs, cymbals consist of thin, normally round plates of various alloys. The majority of cymbals are of indefinite pitch, although small disc-shaped cymbals based on ancient designs soun ...

s because of its greater resilience, leading to broader tonal spectrum and greater sustain. Phosphor bronze is one of several high copper content alloys used as a substitute for the more common "yellow" or "cartridge" types of

to construct the bodies and bells of metal

wind instruments A wind instrument is a musical instrument that contains some type of resonator (usually a tube) in which a column of air is set into vibration by the player blowing into (or over) a mouthpiece set at or near the end of the resonator. The pit ...

. Examples of instruments constructed using high copper alloys occur among members of the

brass instrument A brass instrument is a musical instrument that produces sound by sympathetic vibration of air in a tubular resonator in sympathy with the vibration of the player's lips. Brass instruments are also called labrosones or labrophones, from Latin a ...

family (

trumpet The trumpet is a brass instrument commonly used in classical and jazz ensembles. The trumpet group ranges from the piccolo trumpet—with the highest register in the brass family—to the bass trumpet, pitched one octave below the standard ...

flugelhorn The flugelhorn (), also spelled fluegelhorn, flugel horn, or flügelhorn, is a brass instrument that resembles the trumpet and cornet but has a wider, more conical bore. Like trumpets and cornets, most flugelhorns are pitched in B, though som ...

s, and

trombones The trombone (german: Posaune, Italian, French: ''trombone'') is a musical instrument in the brass family. As with all brass instruments, sound is produced when the player's vibrating lips cause the air column inside the instrument to vibrate ...

) and one member of the

reed instrument Reed aerophones is one of the categories of musical instruments found in the Hornbostel-Sachs system of musical instrument classification. In order to produce sound with these Aerophones the player's breath is directed against a lamella or pair ...

family,

saxophone The saxophone (often referred to colloquially as the sax) is a type of Single-reed instrument, single-reed woodwind instrument with a conical body, usually made of brass. As with all single-reed instruments, sound is produced when a reed (mouthpi ...

s. In addition to the distinctive appearance provided by the reddish-orange hue of high copper alloys, they are purported by some instrument designers, sellers, and players to provide a broader harmonic response spectrum for a given instrument design. The Yanagisawa 902/992 model saxophones (pictured) have bodies of phosphor bronze, in contrast to the brass 901/991 models. Some instrument strings for

acoustic guitar An acoustic guitar is a musical instrument in the string family. When a string is plucked its vibration is transmitted from the bridge, resonating throughout the top of the guitar. It is also transmitted to the side and back of the instrument, ...

mandolin A mandolin ( it, mandolino ; literally "small mandola") is a stringed musical instrument in the lute family and is generally plucked with a pick. It most commonly has four courses of doubled strings tuned in unison, thus giving a total of ...

s and

violins The violin, sometimes known as a ''fiddle'', is a wooden chordophone (string instrument) in the violin family. Most violins have a hollow wooden body. It is the smallest and thus highest-pitched instrument (soprano) in the family in regular ...

are wrapped with phosphor bronze. Some

harmonica The harmonica, also known as a French harp or mouth organ, is a free reed wind instrument used worldwide in many musical genres, notably in blues, American folk music, classical music, jazz, country, and rock. The many types of harmonica in ...

reeds are made of phosphor bronze, such as those by

Suzuki Musical Instrument Corporation The is a Japanese company that produces a range of musical instruments. History Suzuki was founded in 1953 by Mr. Manji Suzuki. Initially the company manufactured Harmonicas and later developed the Melodion which in 1956 was officially adopted ...

and Bushman Harmonicas. The reed component of reed-type organ pipes is usually made of phosphor bronze owing to its high wear and low deformability under conditions of constant vibration when producing sound. Some snare drums are constructed with phosphor bronze.

Variants

Further increasing the phosphorus content leads to formation of a very hard compound Cu₃P (

copper phosphide Copper phosphide, , also copper(I) phosphide, cuprous phosphide, cuprophosphorus and phosphor copper, is a compound of copper Copper is a chemical element with the symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleabl ...

), resulting in a brittle form of phosphor bronze, which has a narrow range of applications. Around 2001, the Olin Corporation developed another alloy for use in electrical and electronic connectors which they referred to as "phosphor bronze". Its composition was as follows: *

Zinc Zinc is a chemical element with the symbol Zn and atomic number 30. Zinc is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodi ...

– 9.9% * Tin – 2.2% *

Iron Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in ...

– 1.9% *

Phosphorus Phosphorus is a chemical element with the symbol P and atomic number 15. Elemental phosphorus exists in two major forms, white phosphorus and red phosphorus, but because it is highly reactive, phosphorus is never found as a free element on Ea ...

– 0.03% *

Copper Copper is a chemical element with the symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pink ...

– 85.97% When assessed in strictly metallurgical terms it is not a phosphor bronze, but a form of iron-modified tin

References

External links

Copper and copper alloy microstructures: Phosphor bronze
{{Authority control Belgian inventions Copper alloys Bronze