Fauteuil et décors de porte de Peter Behrens (Musée de la colonie d'artistes, Darmstadt) (8729765938)

Aluminium bronze is a type of bronze in which

aluminium Aluminium (aluminum in AmE, American and CanE, Canadian English) is a chemical element with the Symbol (chemistry), symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately o ...

is the main

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, ductilit ...

ing

metal A metal (from Greek μέταλλον ''métallon'', "mine, quarry, metal") is a material that, when freshly prepared, polished, or fractured, shows a lustrous appearance, and conducts electricity and heat relatively well. Metals are typi ...

added to

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 pinkish ...

, in contrast to standard bronze (copper and tin) or

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 wit ...

(copper and zinc). A variety of aluminium bronzes of differing compositions have found industrial use, with most ranging from 5% to 11% aluminium by weight, the remaining mass being copper; other alloying agents such as

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 ...

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 ...

manganese Manganese is a chemical element with the symbol Mn and atomic number 25. It is a hard, brittle, silvery metal, often found in minerals in combination with iron. Manganese is a transition metal with a multifaceted array of industrial alloy u ...

, and

silicon Silicon is a chemical element with the symbol Si and atomic number 14. It is a hard, brittle crystalline solid with a blue-grey metallic luster, and is a tetravalent metalloid and semiconductor. It is a member of group 14 in the periodic ...

are also sometimes added to aluminium bronzes.

Compositions

The following table lists the most common standard aluminium bronze wrought alloy compositions, by ISO 428 designations. The percentages show the proportional composition of the alloy by weight. Copper is the remainder by weight and is not listed:

Material properties

Aluminium bronzes are most valued for their higher strength and

corrosion Corrosion is a natural process that converts a refined metal into a more chemically stable oxide. It is the gradual deterioration of materials (usually a metal) by chemical or electrochemical reaction with their environment. Corrosion engi ...

resistance as compared to other bronze alloys. These alloys are tarnish-resistant and show low rates of corrosion in

atmospheric An atmosphere () is a layer of gas or layers of gases that envelop a planet, and is held in place by the gravity of the planetary body. A planet retains an atmosphere when the gravity is great and the temperature of the atmosphere is low. A s ...

conditions, low

oxidation Redox (reduction–oxidation, , ) is a type of chemical reaction in which the oxidation states of substrate change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is the gain of electrons or a ...

rates at high temperatures, and low reactivity with

sulfur Sulfur (or sulphur in British English) is a chemical element with the symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms form cyclic octatomic molecules with a chemical formul ...

ous compounds and other

exhaust Exhaust, exhaustive, or exhaustion may refer to: Law * Exhaustion of intellectual property rights, limits to intellectual property rights in patent and copyright law ** Exhaustion doctrine, in patent law ** Exhaustion doctrine under U.S. law, i ...

products of

combustion Combustion, or burning, is a high-temperature exothermic redox chemical reaction between a fuel (the reductant) and an oxidant, usually atmospheric oxygen, that produces oxidized, often gaseous products, in a mixture termed as smoke. Combust ...

. They are also resistant to corrosion in sea water. Aluminium bronzes' resistance to corrosion results from the aluminium in the alloys, which reacts with atmospheric

oxygen Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as we ...

to form a thin, tough surface layer of alumina (aluminium oxide) which acts as a barrier to corrosion of the copper-rich alloy. The addition of tin can improve corrosion resistance. Another notable property of aluminium bronzes are their biostatic effects. The copper component of the alloy prevents colonization by marine organisms including

algae Algae ( , ; : alga ) are any of a large and diverse group of photosynthetic, eukaryotic organisms. The name is an informal term for a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from ...

, lichens,

barnacle A barnacle is a type of arthropod constituting the subclass Cirripedia in the subphylum Crustacea, and is hence related to crabs and lobsters. Barnacles are exclusively marine, and tend to live in shallow and tidal waters, typically in erosive ...

s, and

mussel Mussel () is the common name used for members of several families of bivalve molluscs, from saltwater and freshwater habitats. These groups have in common a shell whose outline is elongated and asymmetrical compared with other edible clams, whic ...

s, and therefore can be preferable to stainless steel or other non-cupric alloys in applications where such colonization would be unwanted. Aluminium bronzes tend to have a golden color.

Applications

Aluminium bronzes are most commonly used in applications where their resistance to corrosion makes them preferable to other engineering materials. These applications include

plain bearing A plain bearing, or more commonly sliding contact bearing and slide bearing (in railroading sometimes called a solid bearing, journal bearing, or friction bearing), is the simplest type of bearing, comprising just a bearing surface and no roll ...

s and

landing gear Landing gear is the undercarriage of an aircraft or spacecraft that is used for takeoff or landing. For aircraft it is generally needed for both. It was also formerly called ''alighting gear'' by some manufacturers, such as the Glenn L. Marti ...

components on

aircraft An aircraft is a vehicle that is able to fly by gaining support from the air. It counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines. ...

, guitar strings, valve components,

engine An engine or motor is a machine designed to convert one or more forms of energy into mechanical energy. Available energy sources include potential energy (e.g. energy of the Earth's gravitational field as exploited in hydroelectric power ...

components (especially for seagoing ships), underwater fastenings in

naval architecture Naval architecture, or naval engineering, is an engineering discipline incorporating elements of mechanical, electrical, electronic, software and safety engineering as applied to the engineering design process, shipbuilding, maintenance, and ...

, and ship

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. Aluminium bronze is also used to fulfil the ATEX directive for Zones 1, 2, 21, and 22. The attractive gold-toned coloration of aluminium bronzes has also led to their use in

jewellery Jewellery ( UK) or jewelry ( U.S.) consists of decorative items worn for personal adornment, such as brooches, rings, necklaces, earrings, pendants, bracelets, and cufflinks. Jewellery may be attached to the body or the clothes. From a we ...

. Aluminium bronzes are in the highest demand from the following industries and areas: *General sea water-related service *

Water supply Water supply is the provision of water by public utilities, commercial organisations, community endeavors or by individuals, usually via a system of pumps and pipes. Public water supply systems are crucial to properly functioning societies. T ...

* Oil and

petrochemical Petrochemicals (sometimes abbreviated as petchems) are the chemical products obtained from petroleum by refining. Some chemical compounds made from petroleum are also obtained from other fossil fuels, such as coal or natural gas, or renewable ...

industries (''i.e.'' tools for use in non-sparking environments) *Specialised anti-corrosive applications *Certain structural retrofit building applications Aluminium bronze can be welded using the MIG welding technique with an aluminium bronze core and pure

argon Argon is a chemical element with the symbol Ar and atomic number 18. It is in group 18 of the periodic table and is a noble gas. Argon is the third-most abundant gas in Earth's atmosphere, at 0.934% (9340 ppmv). It is more than twice as a ...

gas. Aluminium bronze is used to replace gold for the casting of dental crowns. The alloys used are chemically inert and have the appearance of gold. Italy pioneered the use for coinage of an aluminium-bronze alloy called bronzital (literally "Italian bronze") in its 5- and 10-centesimi from 1939. Its alloy was finalized in 1967 to 92% copper, 6% aluminium, and 2% nickel, and was since used in the 20, 200 and 500

Italian Lira The lira (; plural lire) was the currency of Italy between 1861 and 2002. It was first introduced by the Napoleonic Kingdom of Italy in 1807 at par with the French franc, and was subsequently adopted by the different states that would eventually ...

coins until 2001. Bronzital has since been used for the Australian and

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 List of islands of New Zealand, smaller islands. It is the ...

1- and 2-dollar coins, the pre-2009 Mexican 20- and 50-centavo coins, the inner cores of the bi-metallic Mexican 1-, 2- and 5-peso coins, the pre-2017 Philippine 10-peso coin, the Canadian 2 dollar coin (a.k.a. the 'toonie'), and the outer rings of the Mexican 10-, 20-, 50- and 100-peso coins. Nordic gold, composed of 89% copper, 5% aluminium, 5% zinc, and 1% tin, is a more recently developed aluminium-bronze alloy for coinage. It was first used for the Swedish 10-kronor coin in 1991, and became widespread after the introduction of Nordic gold 10, 20 and 50-cent Euro coins in 2002.

References

External links

* *Copper Development Association
"Publication Number 80: Aluminium Bronze Alloys Corrosion Resistance Guide", PDF
. Retrieved April 9, 2014. *Copper Development Association
"Publication Number 82: Aluminium Bronze Alloys Technical Data"
Retrieved April 9, 2014. {{Authority control Bronze Copper alloys