Bronze is a metal alloy An alloy is a partial or complete solid solution of one or more elements in a metallic matrix. Complete solid solution alloys give single solid phase microstructure, while partial solutions give two or more phases that may be homogeneous in distribution depending on thermal history. Alloys usually have different properties from those of the consisting primarily of copper Copper is a chemical element with the symbol Cu (Latin: cuprum) and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is rather soft and malleable, and a freshly exposed surface has a pinkish or peachy color. It is used as a thermal conductor, an electrical conductor, a building material, and a, usually with tin Tin is a chemical element with the symbol Sn and atomic number 50. It is a main group metal in group 14 of the periodic table. Tin shows chemical similarity to both neighboring group 14 elements, germanium and lead, like the two possible oxidation states +2 and +4. Tin is the 49th most abundant element and has, with 10 stable isotopes, the largest as the main additive, but sometimes with other elements A chemical element is a pure chemical substance consisting of one type of atom distinguished by its atomic number, which is the number of protons in its nucleus. The term is also used to refer to a pure chemical substance composed of atoms with the same number of protons. Common examples of elements are iron, copper, silver, gold, hydrogen, carbon, such as phosphorus Phosphorus is the chemical element that has the symbol P and atomic number 15. A multivalent nonmetal of the nitrogen group, phosphorus is commonly found in inorganic phosphate rocks. Elemental phosphorus exists in two major forms – white phosphorus and red phosphorus. Although the term "phosphorescence", meaning glow after, manganese Manganese is a chemical element, designated by the symbol Mn. It has the atomic number 25. It is found as a free element in nature (often in combination with iron), and in many minerals. As a free element, manganese is a metal with important industrial metal alloy uses, particularly in stainless steels, aluminium Aluminium (UK: /ˌæljʉˈmɪniəm/ AL-yew-MIN-ee-əm) or aluminum (US: /əˈluːmɨnəm/ ( listen) ə-LOO-mi-nəm) is a silvery white member of the boron group of chemical elements. It has the symbol Al and its atomic number is 13. It is not soluble in water under normal circumstances. Aluminium is the most abundant metal in the Earth's crust,, or silicon Silicon is the most common metalloid. It is a chemical element, which has the symbol Si and atomic number 14. A tetravalent metalloid, silicon is less reactive than its chemical analog carbon. It is hard and brittle, and it was particularly significant in antiquity, so much so that the Bronze Age The Bronze Age of a culture is the period when the most advanced metalworking in that culture used bronze. This could either have been based on the local smelting of copper and tin from ores, or trading for bronze from production areas elsewhere. Many, though not all, Bronze Age cultures flourished in prehistory was named after the metal.

The word Bronze is believed to be cognate with the Italian Italian ( italiano , or lingua italiana) is a Romance language spoken as a native language by about 70 million people in Italy, San Marino and parts of Switzerland, Croatia, Slovenia and France. In addition, it is spoken by an additional 120 to 150 million people as a non-native language. Most native speakers are native bilinguals of both: bronzo and German: brunst, perhaps ultimately taken from the Persian Persian is an Iranian language within the Indo-Iranian branch of the Indo-European languages. It is widely spoken in Iran, Afghanistan, Tajikistan, Uzbekistan and to some extent in Iraq, Bahrain, and Oman. New Persian, which usually is called also by the names of Farsi, Parsi, Dari or Parsi-ye-Dari (Dari Persian), can be classified linguistically word birinj ("bronze") or possibly from the Latin name of the city of Brindisi Brindisi listen is a city in the Apulia region of Italy, the capital of the province of Brindisi, off the coast of the Adriatic Sea (aes Brundusinum -Pliny).^[1]

History

The discovery of bronze enabled people to create metal objects which were better than was previously possible. Tools, weapons, armor, and various building materials Building material is any material which is used for a construction purpose. Many naturally occurring substances, such as clay, sand, wood and rocks, even twigs and leaves have been used to construct buildings. Apart from naturally occurring materials, many man-made products are in use, some more and some less synthetic. The manufacture of building, like decorative tiles, made of bronze were harder and more durable than their stone and copper ("Chalcolithic The Chalcolithic period or Copper Age period, also known as the Eneolithic/Æneolithic (from Latin aeneus "of bronze"), is a phase in the development of human culture in which the use of early metal tools appeared alongside the use of stone tools") predecessors. Initially bronze was made out of copper and arsenic Arsenic is the chemical element that has the symbol As, atomic number 33 and atomic mass 74.92. Arsenic was first documented by Albertus Magnus in 1250. Arsenic is a notoriously poisonous metalloid with many allotropic forms, including a yellow (molecular non-metallic) and several black and grey forms (metalloids). Three metalloidal forms of to form arsenic bronze Arsenical bronze is an alloy in which arsenic is added to copper as opposed to, or in addition to other constituent metals. The use of arsenic in bronze, either as the secondary constituent or with another component such as tin, results in a stronger final product. It was only later that tin Tin is a chemical element with the symbol Sn and atomic number 50. It is a main group metal in group 14 of the periodic table. Tin shows chemical similarity to both neighboring group 14 elements, germanium and lead, like the two possible oxidation states +2 and +4. Tin is the 49th most abundant element and has, with 10 stable isotopes, the largest was used, becoming the sole type of bronze in the late 3rd millennium BC. Tin bronze was superior over arsenic bronze in that the alloying process itself could more easily be controlled (as tin was available as a metal) and the alloy was stronger and easier to cast. Also, unlike arsenic, tin is not toxic.

The earliest tin-alloy bronzes date to the late 4th millennium BC in Susa Susa (Persian: Ŝuŝ, pronounced [ʃuʃ]; also Armenian ; Greek: Σοῦσα [sousa]); Syriac: ܫܘܫ (Shush); Old Persian Çūšā-; Biblical Hebrew שׁוּשָׁן (Shushān); was an ancient city of the Elamite, Persian and Parthian empires of Iran. It is located in the lower Zagros Mountains about 250 km (150 miles) east of the Tigris River, (Iran Iran (Persian: ایران [ʔiˈɾɒn] ), officially the Islamic Republic of Iran is a country in Central Eurasia and Western Asia. The name Iran has been in use natively since the Sassanian era and came into use internationally in 1935, before which the country was also known to the western world as Persia. Both Persia and Iran are used) and some ancient sites in Luristan Lorestân, Lurestaan or Luristan, comprises a province and a historic territory of western Iran amidst the Zagros Mountains. The population of Lorestān was estimated at 1,716,527 people in 2006 (Iran) and Mesopotamia Mesopotamia is a toponym for the area of the Tigris-Euphrates river system, largely corresponding to modern-day Iraq, as well as some parts of northeastern Syria, southeastern Turkey, and southwestern Iran (Iraq Iraq , officially the Republic of Iraq (Arabic: جمهورية العراق (help·info) Jumhūrīyat Al-Irāq, Kurdish: كؤماری عێراق‎, Komara Îraqê) is a country in Western Asia spanning most of the northwestern end of the Zagros mountain range, the eastern part of the Syrian Desert and the northern part of the Arabian Desert).

Copper and tin ores An ore is a type of rock that contains minerals with important elements including metals. The ores are extracted through mining; these are then refined to extract the valuable element are rarely found together (exceptions include one ancient site in Thailand Thailand (pronounced /ˈtaɪlænd/ TYE-land or /ˈtaɪlənd/; Thai: ราชอาณาจักรไทย Ratcha Anachak Thai, IPA: [râːtɕʰa ʔaːnaːtɕɑ̀k tʰɑj]) (formerly Siam Thai: สยาม) is an independent country that lies in the heart of Southeast Asia. It is bordered to the north by Burma and Laos, to the east by Laos and one in Iran), so serious bronze work has always involved trade. In Europe, the major source for tin was Great Britain Great Britain is an island situated to the northwest of Continental Europe. It is the ninth largest island in the world, and the largest European island. With a population of about 59.8 million people in mid-2009, it is the third most populated island on Earth. Great Britain is surrounded by over 1,000 smaller islands and islets. The island of's deposits of ore in Cornwall Cornwall is a ceremonial county and unitary authority of England, United Kingdom, forming the tip of the south-western peninsula of Great Britain. It is bordered to the north and west by the Atlantic Ocean, to the south by the English Channel, and to the east by the county of Devon, over the River Tamar. Taken with the Isles of Scilly, Cornwall, which were traded as far as Phoenicia Phoenicia was an ancient civilization centered in the north of ancient Canaan, with its heartland along the coastal regions of modern day Lebanon, Palestine, Syria and Israel. Phoenician civilization was an enterprising maritime trading culture that spread across the Mediterranean during the period 1550 BC to 300 BC. Though ancient boundaries of in the Eastern Mediterranean The Mediterranean Sea is a sea connected to the Atlantic Ocean surrounded by the Mediterranean region and almost completely enclosed by land: on the north by Anatolia and Europe, on the south by North Africa, and on the east by the Levant. The sea is technically a part of the Atlantic Ocean, although it is usually identified as a completely.

Though bronze is generally harder than wrought iron Wrought iron is an iron alloy with a very low carbon content, in comparison to steel, and has fibrous inclusions, known as slag. This is what gives it a "grain" resembling wood, which is visible when it is etched or bent to the point of failure. Wrought iron is tough, malleable, ductile and easily welded. Historically, it was known as &, with Vickers hardness The Vickers hardness test was developed in 1924 by Smith and Sandland at Vickers Ltd as an alternative to the Brinell method to measure the hardness of materials. The Vickers test is often easier to use than other hardness tests since the required calculations are independent of the size of the indenter, and the indenter can be used for all of 60–258^[2] vs. 30–80,^[3] the Bronze Age The Bronze Age of a culture is the period when the most advanced metalworking in that culture used bronze. This could either have been based on the local smelting of copper and tin from ores, or trading for bronze from production areas elsewhere. Many, though not all, Bronze Age cultures flourished in prehistory gave way to the Iron Age In archaeology, the Iron Age is the historical period in any area during which cutting tools and weapons were mainly made of iron or steel. The adoption of this material coincided with other changes in society, including differing agricultural practices, religious beliefs and artistic styles; this happened because iron was easier to find. Bronze was still used during the Iron Age, but, for many purposes, the weaker wrought iron was found to be sufficiently strong. Archaeologists suspect that a serious disruption of the tin trade precipitated the transition. The population migrations around 1200–1100 BC reduced the shipping of tin around the Mediterranean (and from Great Britain), limiting supplies and raising prices.^[4] As ironworking improved, iron Iron is the most common element in the earth as a whole, and the fourth most common in the Earth's crust. It is produced as a result of stellar fusion in high-mass stars, and it is the heaviest stable element produced by stellar fusion because the fusion of iron is the last nuclear fusion reaction that is exothermic. Iron is the most widely used became cheaper; and as cultures advanced from wrought iron to forged iron, they learned how to make steel Steel is an alloy that consists mostly of iron and has a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most common alloying material for iron, but various other alloying elements are used, such as manganese, chromium, vanadium, and tungsten. Carbon and other elements act as a hardening agent, preventing, which is stronger than bronze and holds a sharper edge longer.^[5]

Composition

There are many different bronze alloys but bronze is typically 88% copper Copper is a chemical element with the symbol Cu (Latin: cuprum) and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is rather soft and malleable, and a freshly exposed surface has a pinkish or peachy color. It is used as a thermal conductor, an electrical conductor, a building material, and a and 12% tin Tin is a chemical element with the symbol Sn and atomic number 50. It is a main group metal in group 14 of the periodic table. Tin shows chemical similarity to both neighboring group 14 elements, germanium and lead, like the two possible oxidation states +2 and +4. Tin is the 49th most abundant element and has, with 10 stable isotopes, the largest.^[6] Alpha bronze consists of the alpha solid solution A solid solution is a solid-state solution of one or more solutes in a solvent. Such a mixture is considered a solution rather than a compound when the crystal structure of the solvent remains unchanged by addition of the solutes, and when the mixture remains in a single homogeneous phase.This often happens when the two elements involved are close of tin in copper. Alpha bronze alloys of 4–5% tin are used to make coins Coins are usually metal or a metallic material and sometimes made of synthetic materials, usually in the shape of a disc, and most often issued by a government. Coins are used as a form of money in transactions of various kinds, from the everyday circulation coins to the storage of large numbers of bullion coins. In the present day, coins and, springs A spring is an elastic object used to store mechanical energy. Springs are usually made out of hardened steel. Small springs can be wound from pre-hardened stock, while larger ones are made from annealed steel and hardened after fabrication. Some non-ferrous metals are also used including phosphor bronze and titanium for parts requiring corrosion, turbines A turbine is a rotary engine that extracts energy from a fluid flow and converts it into useful work and blades A blade is the flat part of a tool, weapon, or machine that normally has a cutting edge and/or pointed end typically made of a flaking stone, such as flint, or metal, most recently steel. A blade is used to cut, stab, slash, chop, slice, thrust, position and/or place (an example of this is razor wire), or scrape (an example of this is an ink.

Commercial bronze (90% copper and 10% zinc) and Architectural bronze (57% Copper, 3% Lead, 40% Zinc) are actually brass 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. In comparison, bronze is principally an alloy of copper and tin. Despite this distinction some types of brasses are called bronzes and vice-versa. Brass is a substitutional alloy. It is used for decoration alloys because they contain zinc as the main alloying ingredient. They are commonly used in architectural applications.^[7][8]

Bismuth bronze is a bronze alloy with a composition of 52 parts copper, 30 parts nickel, 12 parts zinc, 5 parts lead, and 1 part bismuth. It is able to hold a good polish and so is sometimes used in light reflectors and mirrors.^[9]

Other bronze alloys include Aluminium bronze Aluminium bronze is a type of bronze in which aluminium is the main alloying metal added to copper. 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, nickel, manganese, and silicon are also, Phosphor bronze Phosphor bronze is an alloy of copper with 3.5 to 10% of tin and a significant phosphorus content of up to 1%. The phosphorus is added as deoxidizing agent during melting, Manganese bronze, Bell metal, Speculum metal Speculum metal is a mixture of around two-thirds copper and one-third tin making a white brittle alloy that can be polished to make a highly reflective surface. It is used primarily to make different kinds of mirrors including early reflecting telescope optical mirrors. Speculum metal can also be used as the metallic coating on glass mirrors and Cymbal alloys.

Properties

Bronze is considerably less brittle A material is brittle if it is liable to fracture when subjected to stress. That is, it has little tendency to deform before fracture. This fracture absorbs relatively little energy, even in materials of high strength, and usually makes a snapping sound than iron. Typically bronze only oxidizes superficially; once a copper oxide (eventually becoming copper carbonate) layer is formed, the underlying metal is protected from further corrosion. However, if copper chlorides are formed, a corrosion-mode called "bronze disease" will eventually completely destroy it.^[10] Copper-based alloys An alloy is a partial or complete solid solution of one or more elements in a metallic matrix. Complete solid solution alloys give single solid phase microstructure, while partial solutions give two or more phases that may be homogeneous in distribution depending on thermal history. Alloys usually have different properties from those of the have lower melting points than steel or iron, and are more readily produced from their constituent metals. They are generally about 10 percent heavier than steel, although alloys using aluminium or silicon may be slightly less dense. Bronzes are softer and weaker than steel—bronze springs, for example, are less stiff (and so store less energy) for the same bulk. Bronze resists corrosion (especially seawater corrosion) and metal fatigue more than steel and is also a better conductor of heat and electricity than most steels. The cost of copper-base alloys is generally higher than that of steels but lower than that of nickel-base alloys.

Copper and its alloys have a huge variety of uses that reflect their versatile physical, mechanical, and chemical properties. Some common examples are the high electrical conductivity of pure copper, the excellent deep drawing qualities of cartridge case brass, the low-friction properties of bearing bronze, the resonant qualities of bell bronze, and the resistance to corrosion by sea water of several bronze alloys.

The melting point of Bronze varies depending on the actual ratio of the alloy components and is about 950 °C.

Uses

Bronze was especially suitable for use in boat and ship fittings prior to the wide employment of stainless steel owing to its combination of toughness and resistance to salt water corrosion. Bronze is still commonly used in ship propellers and submerged bearings.

In the twentieth century, silicon was introduced as the primary alloying element, creating an alloy with wide application in industry and the major form used in contemporary statuary. Aluminium is also used for the structural metal aluminium bronze.

It is also widely used for cast bronze sculpture. Many common bronze alloys have the unusual and very desirable property of expanding slightly just before they set, thus filling in the finest details of a mould. Bronze parts are tough and typically used for bearings, clips, electrical connectors and springs.

Spring bronze weatherstripping comes in rolls of thin sheets and is nailed or stapled to wood windows and doors. There are two types, flat and v-strip. It has been used for hundreds of years because it has low friction, seals well and is long lasting. It is used in building restoration and custom construction.

Bronze also has very little metal-on-metal friction, which made it invaluable for the building of cannon where iron cannonballs would otherwise stick in the barrel.^{[citation needed]} It is still widely used today for springs, bearings, bushings, automobile transmission pilot bearings, and similar fittings, and is particularly common in the bearings of small electric motors. Phosphor bronze is particularly suited to precision-grade bearings and springs. It is also used in guitar and piano strings.

Unlike steel, bronze struck against a hard surface will not generate sparks, so it (along with beryllium copper) is used to make hammers, mallets, wrenches and other durable tools to be used in explosive atmospheres or in the presence of flammable vapours.

Bronze statues

Indian Hindu artisans from the period of the Chola empire in Tamil Nadu, used bronze to create intricate statues via the lost wax casting method with ornate detailing depicting the Gods of Hinduism mostly, but also the lifestyle of the period. The art form survives to this day, with many silpis, craftsmen, working in the areas of Swamimalai and Chennai.

In antiquity other cultures also produced works of high art using bronze. For example: in Africa, the bronze heads of the Kingdom of Benin; in Europe, Grecian bronzes typically of figures from Greek mythology; in east Asia, Chinese bronzes of the Shang and Zhou dynasty — more often ceremonial vessels but including some figurine examples.

Bronze continues into modern times as one of the materials of choice for monumental statuary.

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