Beryllium copper (BeCu), also known as copper beryllium (CuBe), beryllium bronze, and spring copper, is a

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 ...

alloy 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, ductili ...

with 0.5–3%

beryllium Beryllium is a chemical element with the symbol Be and atomic number 4. It is a steel-gray, strong, lightweight and brittle alkaline earth metal. It is a divalent element that occurs naturally only in combination with other elements to for ...

but can contain other elements as well. Beryllium copper combines high strength with non-

magnetic Magnetism is the class of physical attributes that are mediated by a magnetic field, which refers to the capacity to induce attractive and repulsive phenomena in other entities. Electric currents and the magnetic moments of elementary particl ...

and non-sparking qualities. It has excellent

metalworking Metalworking is the process of shaping and reshaping metals to create useful objects, parts, assemblies, and large scale structures. As a term it covers a wide and diverse range of processes, skills, and tools for producing objects on every scale ...

, forming, and machining properties. It has many specialized applications in tools for hazardous environments, musical instruments, precision measurement devices, bullets, and aerospace. Beryllium alloys present a toxic inhalation hazard during manufacture.

Properties

Beryllium copper is a ductile, weldable, and machinable alloy. Like pure copper, it is resistant to non-oxidizing acids (such as

hydrochloric acid Hydrochloric acid, also known as muriatic acid, is an aqueous solution of hydrogen chloride. It is a colorless solution with a distinctive pungent smell. It is classified as a strong acid. It is a component of the gastric acid in the dige ...

and carbonic acid) and plastic decomposition products, to abrasive wear, and to

galling Galling is a form of wear caused by adhesion between sliding surfaces. When a material galls, some of it is pulled with the contacting surface, especially if there is a large amount of force compressing the surfaces together. Galling is cau ...

. It can be heat-treated for increased strength, durability, and

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 ...

. Beryllium copper attains the greatest strength (up to ) of any copper-based alloy. It has good

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 ...

(62 Btu/ft-deg.F-H), 3-5 times more than tool steel. It has a solid melting point of 1590 ° F (866 ° C) and a liquid melting point of 1800 °F (982 °C). It has an excellent capacity for being hot-formed. C17200 Beryllium Copper alloy has strength and hardness similar to that of

steel Steel is an alloy made up of iron with added carbon to improve its strength and fracture resistance compared to other forms of iron. Many other elements may be present or added. Stainless steels that are corrosion- and oxidation-resistan ...

; Rockwell hardness properties in its peaked age condition are in the range of 200 ksi and RC45. C17200 has excellent corrosion-resistant properties when exposed to harsh conditions such as seawater, and down-hole environments. It will withstand sulphide or chloride stress corrosion cracking and will resist the effects of carbon dioxide and hydrogen embrittlement. Copper alloys in general have always been considered non-sparking. C17200 has the strength to withstand the use of hand and mechanical tools. These non-sparking features are best applied in explosive environments such as in the Oil & Gas and gunpowder industries.

Toxicity

Inhalation of dust, mist, or fume containing beryllium can cause the serious lung condition chronic beryllium disease, which restricts the exchange of oxygen between the lungs and the bloodstream. The

International Agency for Research on Cancer The International Agency for Research on Cancer (IARC; french: Centre International de Recherche sur le Cancer, CIRC) is an intergovernmental agency forming part of the World Health Organization of the United Nations. Its role is to conduct and ...

(IARC) lists beryllium as a Group 1 Human Carcinogen. The National Toxicology Program (NTP) also lists beryllium as a carcinogen. Copper beryllium alloy containing less than 2.5% Beryllium (in Copper) is not designated as a carcinogen. The current OSHA PELs for pure beryllium is 2 micrograms (µg) per cubic meter as an 8-hour TWA, 5 µg/m³ as a ceiling not to be exceeded for more than 30 minutes at a time, and 25 µg/m³ as a peak exposure never to be exceeded. The OSHA limits have been in place for nearly 30 years and have not been revised in that time. The American Conference of Governmental Industrial Hygienists (ACGIH) current Threshold Limit Value (TLV)* for beryllium is 0.05 µg/m³ averaged over an 8-hour work shift pdated 02/23/2010

Uses

Beryllium copper is a non-ferrous alloy used in springs, spring wire, load cells, and other parts that must retain their shape under repeated stress and strain. It has high electrical conductivity and is used in low-current contacts for batteries and electrical connectors. Beryllium copper is non- sparking but physically tough and nonmagnetic, fulfilling the requirements of

ATEX directive The ATEX directives are two EU directives describing the minimum safety requirements for workplaces and equipment used in explosive atmospheres. The name is an initialization of the French term ''Appareils destinés à être utilisés en ATmo ...

for Zones 0, 1, and 2. Beryllium copper

screwdriver A screwdriver is a tool, manual or powered, used for turning screws. A typical simple screwdriver has a handle and a shaft, ending in a tip the user puts into the screw head before turning the handle. This form of the screwdriver has been repla ...

s, pliers,

wrench A wrench or spanner is a tool used to provide grip and mechanical advantage in applying torque to turn objects—usually rotary fasteners, such as nuts and bolts—or keep them from turning. In the UK, Ireland, Australia, and New Zeal ...

es, cold chisels, knives, and hammers are available for environments with

explosive An explosive (or explosive material) is a reactive substance that contains a great amount of potential energy that can produce an explosion if released suddenly, usually accompanied by the production of light, heat, sound, and pressure. An expl ...

hazards, such as oil rigs, coal mines, and grain elevators. An alternative metal sometimes used for non-sparking tools is Aluminium Bronze. Compared to

tools, beryllium copper tools are more expensive and not as strong, but the properties of beryllium copper in hazardous environments may outweigh the disadvantages. Some other uses include: *Some percussion instruments, especially

tambourine The tambourine is a musical instrument in the percussion family consisting of a frame, often of wood or plastic, with pairs of small metal jingles, called " zills". Classically the term tambourine denotes an instrument with a drumhead, tho ...

s and triangles, because of beryllium copper's consistent tone and resonance. *Ultra-low temperature

cryogenic 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 “cr ...

equipment, such as

dilution refrigerator A 3He/4He dilution refrigerator is a cryogenic device that provides continuous cooling to temperatures as low as 2 mK, with no moving parts in the low-temperature region. The cooling power is provided by the heat of mixing of the He ...

s, because of its mechanical strength and relatively high thermal conductivity in this temperature range. *Moulds for manufacturing plastic containers (including virtually every plastic milk jug), with the blow moulding process. * Armour-piercing

bullet A bullet is a kinetic projectile, a component of firearm ammunition that is shot from a gun barrel. Bullets are made of a variety of materials, such as copper, lead, steel, polymer, rubber and even wax. Bullets are made in various shapes and co ...

s, though such usage is unusual because bullets made from steel alloys are much less expensive and have similar properties. *Measurement-while-drilling (MWD) tools in the

directional drilling Directional drilling (or slant drilling) is the practice of drilling non-vertical bores. It can be broken down into four main groups: oilfield directional drilling, utility installation directional drilling, directional boring (horizontal dire ...

industry. A non-magnetic alloy is required, as magnetometers are used for field-strength data received from the tool. *Servicing magnetic resonance imaging (MRI) machines, where high-strength magnetic fields make the use of ferrous tools dangerous, and where magnetic materials in the field can disturb the image. *Gaskets used to create an RF-tight (resistant to radio frequency leakage), the electronic seal on doors used with EMC testing, and anechoic chambers. *In the 1980s, beryllium copper was used in the manufacture of golf clubs, particularly wedges and putters. Though some golfers prefer the feel of BeCu club heads, regulatory issues and high costs have made BeCu clubs difficult to find in current production. *Kiefer Plating (defunct) of Elkhart, Indiana built beryllium-copper trumpet bells for the Schilke Music Co. of Chicago. These lightweight bells produce a sound preferred by some musicians. Beryllium copper wire is produced in many forms: round, square, flat, and shaped, in coils, on spools, and in straight lengths. Beryllium copper valve seats and guides are used in high-performance four-stroke engines with coated titanium valves. BeCu dissipates heat from the valve as much as seven times faster than powdered steel or iron seats & guides. The softer BeCu reduces valve wear and increases valve life.

Alloys

Beryllium copper (C17200 & C17300) is an age-hardening alloy that attains the highest strength of any copper base alloy. It may be age hardened after forming into springs, intricate forms, or complex shapes. It is valued for spring properties, corrosion resistance, stability, conductivity, and low creep. Tempered beryllium copper is C17200 & C17300 which has been age-hardened and cold-drawn. No further heat treatment is necessary beyond possible light stress relief. It is sufficiently ductile to wind on its diameter and can be formed into springs and most shapes. The tempered wire is most useful where the properties of beryllium copper are desired, but the age hardening of finished parts is not practical. C17510 and C17500 beryllium copper alloys are age-hardenable and provide good electrical conductivity, physical properties, and endurance. They are used in springs and wire where electrical conduction or retention of properties at elevated temperatures is important. ''High-strength beryllium copper'' alloys contain as much as 2.7% beryllium (cast), or 1.6-2% beryllium with about 0.3%

cobalt Cobalt is a chemical element with the symbol Co and atomic number 27. As with nickel, cobalt is found in the Earth's crust only in a chemically combined form, save for small deposits found in alloys of natural meteoric iron. The free element, p ...

(wrought). The strength is achieved by age hardening. The thermal conductivity of these alloys lies between that of steel and aluminum. The cast alloys are frequently formed with injection moulds. The wrought alloys are designated by UNS as C17200 to C17400, the cast alloys are C82000 to C82800. The hardening process requires rapid cooling of the annealed metal, resulting in a solid-state solution of beryllium in copper, which is then kept at 200-460 °C for at least an hour, producing a precipitation of metastable

beryllide Beryllide is an intermetallic compound of beryllium with other metals, e.g. zirconium, tantalum, titanium, nickel, or cobalt. Typical chemical formulae are Be12Ti and FeBe5. These are hard, metal-like materials that display properties distin ...

crystals in the copper matrix. Over-aging beyond the equilibrium phase depletes the beryllide crystals and reduces their strength. The beryllides in cast alloys are similar to those in wrought alloys. ''High conductivity beryllium copper'' alloys contain as much as 0.7% beryllium with some nickel and cobalt. The thermal conductivity of these alloys is greater than that of aluminum and slightly less than that of pure copper; they are often used as electrical contacts.

References

External links

Standards and properties - Copper and copper alloy microstructures - Copper Beryllium

* ttps://web.archive.org/web/20080302034606/http://www.npi.gov.au/database/substance-info/profiles/27.html National Pollutant Inventory - Copper and compounds fact sheetbr>Copper beryllium and nickel beryllium datasheets
* * * {{DEFAULTSORT:Beryllium Copper Copper alloys Beryllium alloys pl:Brązy#Brąz berylowy