Editing Metal (section)

== Ancient Greece ==
[[File:Aristoteles Louvre.jpg|right|thumb|upright=1.0|alt=A stone sculpture of the head of a bearded man|Greek philosopher [[Aristotle]] (384–322 BCE) categorized substances found in the earth as either metals or minerals.]]
Around 340 BCE, in Book III of his treatise ''[[Meteorology (Aristotle)|Meteorology]]'', the ancient Greek philosopher [[Aristotle]] categorized substances found within the Earth into metals and minerals. The latter category included various minerals such as [[realgar]], [[ochre]], [[red ochre|ruddle]], sulfur, [[cinnabar]], and other substances that he referred to as "stones which cannot be melted".<ref>{{Cite journal |last=Jordan |first=J. M. |date=April 2016 |title='Ancient episteme' and the nature of fossils: a correction of a modern scholarly error |url=http://link.springer.com/10.1007/s40656-015-0094-6 |journal=History and Philosophy of the Life Sciences |language=en |volume=38 |issue=1 |pages=90–116 |doi=10.1007/s40656-015-0094-6 |issn=0391-9714}}</ref>

===Middle Ages===
{{Quote box
| quote=Gold is for the mistress—silver for the maid—<br />Copper for the craftsman cunning at his trade.<br />"Good!" said the Baron, sitting in his hall,<br />"But Iron—Cold Iron—is master of them all."
| salign=right| source=from [[Cold Iron (poem)|Cold Iron]] by [[Rudyard Kipling]]<ref>Published in ''[[The Delineator]]'', Sept. 1909. Reprinted as the introduction to [[Rewards and Fairies]] in 1910.</ref>| bgcolor=Cornsilk
| quoted=1
| width=25em
| align=right
}}
Arabic and medieval [[alchemy|alchemists]] believed that all metals and matter were composed of the principle of sulfur, the father of all metals and carrying the combustible property, and the principle of mercury, the mother of all metals{{#tag:ref|In ancient times, lead was regarded as the father of all metals.|group=n}} and carrier of the liquidity, fusibility, and volatility properties. These principles were not necessarily the common substances [[sulfur]] and [[mercury (element)|mercury]] found in most laboratories. This theory reinforced the belief that all metals were destined to become gold in the bowels of the earth through the proper combinations of heat, digestion, time, and elimination of contaminants, all of which could be developed and hastened through the knowledge and methods of alchemy.{{#tag:ref|[[Paracelsus]], a later [[German Renaissance]] writer, added the third principle of salt, carrying the nonvolatile and incombustible properties, in his [[Paracelsus#Philosophy|''tria prima'' doctrine]]. These theories retained the four classical elements as underlying the composition of sulfur, mercury, and salt.|group=n}}

Arsenic, zinc, antimony, and bismuth became known, although these were at first called semimetals or bastard metals on account of their immalleability. [[Albertus Magnus]] is believed to have been the first to isolate arsenic from a compound in 1250, by heating soap together with [[arsenic trisulfide]]. Metallic zinc, which is brittle if impure, was isolated in India by 1300 AD. The first description of a procedure for isolating antimony is in the 1540 book ''[[De la pirotechnia]]'' by [[Vannoccio Biringuccio]]. Bismuth was described by Agricola in ''[[De Natura Fossilium]]'' (c. 1546); it had been confused in early times with tin and lead because of its resemblance to those elements.

<gallery widths="165px" heights="165px">
File:Arsen 1a.jpg|Arsenic, sealed in a container to prevent tarnishing
File:Zinc fragment sublimed and 1cm3 cube.jpg|Zinc fragments and a 1&nbsp;cm<sup>3</sup> cube
File:Antimony-4.jpg|Antimony, showing its brilliant lustre
File:Wismut Kristall und 1cm3 Wuerfel.jpg|Bismuth in crystalline form, with a very thin oxidation layer, and a 1&nbsp;cm<sup>3</sup> bismuth cube
</gallery>

===The Renaissance===
[[File:Georg Agricola-Titelblatt.jpg|thumb|left|200px|''[[De re metallica]]'', 1555|alt=The title page of De re metallica, which is written in Latin]]
[[File:Platinum crystals.jpg|thumb|left|200px|Platinum crystals|alt=Refer to caption]]
[[File:HEUraniumC.jpg|thumb|left|200px|A disc of highly enriched uranium that was recovered from scrap processed at the [[Y-12 National Security Complex]], in [[Oak Ridge, Tennessee]]|alt=A disc of uranium being held by gloved hands]]
[[File:Cerium2.jpg|thumb|left|200px|Ultrapure cerium under argon, 1.5 gm|alt=Ultrapure cerium under argon]]

The first systematic text on the arts of mining and metallurgy was [[De la pirotechnia|''De la Pirotechnia'']] (1540) by [[Vannoccio Biringuccio]], which treats the examination, fusion, and working of metals.

Sixteen years later, [[Georgius Agricola]] published ''[[De Re Metallica]]'' in 1556, an account of the profession of mining, metallurgy, and the accessory arts and sciences, an extensive treatise on the chemical industry through the sixteenth century.

He gave the following description of a metal in his ''[[De Natura Fossilium]]'' (1546):
<blockquote><div style="font-size:90%">
Metal is a mineral body, by nature either liquid or somewhat hard. The latter may be melted by the heat of the fire, but when it has cooled down again and lost all heat, it becomes hard again and resumes its proper form. In this respect it differs from the stone which melts in the fire, for although the latter regain its hardness, yet it loses its pristine form and properties.

Traditionally there are six different kinds of metals, namely gold, silver, copper, iron, tin, and lead. There are really others, for [[mercury (element)|quicksilver]] is a metal, although the Alchemists disagree with us on this subject, and [[bismuth]] is also. The ancient Greek writers seem to have been ignorant of bismuth, wherefore Ammonius rightly states that there are many species of metals, animals, and plants which are unknown to us. [[Stibium]] when smelted in the crucible and refined has as much right to be regarded as a proper metal as is accorded to lead by writers. If when smelted, a certain portion be added to tin, a bookseller's alloy is produced from which the type is made that is used by those who print books on paper.

Each metal has its own form which it preserves when separated from those metals which were mixed with it. Therefore neither [[electrum]] nor Stannum [not meaning our tin] is of itself a real metal, but rather an alloy of two metals. Electrum is an alloy of gold and silver, Stannum of lead and silver. And yet if silver be parted from the electrum, then gold remains and not electrum; if silver be taken away from Stannum, then lead remains and not Stannum.

Whether brass, however, is found as a native metal or not, cannot be ascertained with any surety. We only know of the artificial brass, which consists of copper tinted with the colour of the mineral [[calamine]]. And yet if any should be dug up, it would be a proper metal. Black and white copper seem to be different from the red kind.

Metal, therefore, is by nature either solid, as I have stated, or fluid, as in the unique case of quicksilver.

But enough now concerning the simple kinds.<ref>Georgius Agricola, [https://www.gutenberg.org/files/38015/38015-h/38015-h.htm ''De Re Metallica''] (1556) Tr. Herbert Clark Hoover & Lou Henry Hoover (1912); Footnote quoting ''De Natura Fossilium'' (1546), p. 180</ref>
</div>
</blockquote>

Platinum, the third precious metal after gold and silver, was discovered in Ecuador during the period 1736 to 1744 by the Spanish astronomer Antonio de Ulloa and his colleague the mathematician Jorge Juan y Santacilia. Ulloa was the first person to write a scientific description of the metal, in 1748.

In 1789, the German chemist Martin Heinrich Klaproth isolated an oxide of uranium, which he thought was the metal itself. Klaproth was subsequently credited as the discoverer of uranium. It was not until 1841, that the French chemist Eugène-Melchior Péligot, prepared the first sample of uranium metal. Henri Becquerel subsequently discovered radioactivity in 1896 using uranium.

In the 1790s, Joseph Priestley and the Dutch chemist Martinus van Marum observed the effect of metal surfaces on the dehydrogenation of alcohol, a development which subsequently led, in 1831, to the industrial scale synthesis of sulphuric acid using a platinum catalyst.

In 1803, cerium was the first of the [[Lanthanide|lanthanide metals]] to be discovered, in Bastnäs, Sweden by Jöns Jakob Berzelius and Wilhelm Hisinger, and independently by Martin Heinrich Klaproth in Germany. The lanthanide metals were regarded as oddities until the 1960s when methods were developed to more efficiently separate them from one another. They have subsequently found uses in cell phones, magnets, lasers, lighting, batteries, catalytic converters, and in other applications enabling modern technologies.

Other metals discovered and prepared during this time were cobalt, nickel, manganese, molybdenum, tungsten, and chromium; and some of the [[platinum group]] metals, palladium, osmium, iridium, and rhodium.

===Light metallic elements===
All elemental metals discovered before 1809 had relatively high densities; their heaviness was regarded as a distinguishing criterion. From 1809 onward, light metals such as sodium, potassium, and strontium were isolated. Their low densities challenged conventional wisdom as to the nature of metals. They behaved chemically as metals however, and were subsequently recognized as such.

Aluminium was discovered in 1824 but it was not until 1886 that an industrial large-scale production method was developed. Prices of aluminium dropped and aluminium became widely used in jewelry, everyday items, eyeglass frames, optical instruments, tableware, and foil in the 1890s and early 20th century. Aluminium's ability to form hard yet light alloys with other metals provided the metal many uses at the time. During World War I, major governments demanded large shipments of aluminium for light and strong airframes.

While pure metallic titanium (99.9%) was first prepared in 1910 it was not used outside the laboratory until 1932. In the 1950s and 1960s, the Soviet Union pioneered the use of titanium in military and submarine applications as part of programs related to the Cold War. Starting in the early 1950s, titanium came into use in military aviation, particularly in high-performance jets, starting with aircraft such as the [[F-100 Super Sabre]] and [[Lockheed A-12]] and [[SR-71]].

Metallic scandium was produced for the first time in 1937. The first pound of 99% pure scandium metal was produced in 1960. Production of aluminium-scandium alloys began in 1971 following a U.S. patent. Aluminium-scandium alloys were also developed in the USSR.
<gallery widths="165" heights="165">
File:Na (Sodium).jpg|Chunks of sodium
File:Potassium-2.jpg|Potassium pearls under paraffin oil. Size of the largest pearl is 0.5&nbsp;cm.
File:Strontium destilled crystals.jpg|Strontium crystals
File:Aluminium-4.jpg|Aluminium chunk,<br />2.6&nbsp;grams, {{nowrap|1=1 x 2 cm}}
File:Titan-crystal bar.JPG|A bar of titanium crystals
File:Scandium sublimed dendritic and 1cm3 cube.jpg|Scandium, including a 1&nbsp;cm<sup>3</sup> cube
</gallery>

===The age of steel===
[[File:Allegheny Ludlum steel furnace.jpg|thumb|right|White-hot steel pours like water from a 35-ton electric furnace, at the Allegheny Ludlum Steel Corporation, in [[Brackenridge, Pennsylvania|Brackenridge]], [[Pennsylvania]].]]

The modern era in [[steelmaking]] began with the introduction of [[Henry Bessemer]]'s [[Bessemer process]] in 1855, the raw material for which was pig iron. His method let him produce steel in large quantities cheaply, thus [[mild steel]] came to be used for most purposes for which wrought iron was formerly used. The [[Gilchrist-Thomas process]] (or ''basic Bessemer process'') was an improvement to the Bessemer process, made by lining the converter with a [[basic (chemistry)|basic]] material to remove phosphorus.

Due to its high [[tensile strength]] and low cost, steel came to be a major component used in [[building]]s, [[infrastructure]], [[tool]]s, [[ship]]s, [[automobile]]s, [[machine]]s, appliances, and [[weapon]]s.

In 1872, the Englishmen Clark and Woods patented an alloy that would today be considered a [[stainless steel]]. The corrosion resistance of iron-chromium alloys had been recognized in 1821 by French metallurgist [[Pierre Berthier]]. He noted their resistance against attack by some acids and suggested their use in cutlery. Metallurgists of the 19th century were unable to produce the combination of low carbon and high chromium found in most modern stainless steels, and the high-chromium alloys they could produce were too brittle to be practical. It was not until 1912 that the industrialization of stainless steel alloys occurred in England, Germany, and the United States.

===The last stable metallic elements===
By 1900 three metals with [[atomic number]]s less than lead (#82), the heaviest stable metal, remained to be discovered: elements 71, 72, 75.

[[Carl Auer von Welsbach|Von Welsbach]], in 1906, proved that the old ytterbium also contained a new element (#71), which he named ''cassiopeium''. [[Georges Urbain|Urbain]] proved this simultaneously, but his samples were very impure and only contained trace quantities of the new element. Despite this, his chosen name ''[[lutetium]]'' was adopted.

In 1908, Ogawa found element 75 in thorianite but assigned it as element 43 instead of 75 and named it ''nipponium''. In 1925 Walter Noddack, Ida Eva Tacke, and Otto Berg announced its separation from gadolinite and gave it the present name, ''[[rhenium]]''.

Georges Urbain claimed to have found element 72 in rare-earth residues, while Vladimir Vernadsky independently found it in orthite. Neither claim was confirmed due to World War I, and neither could be confirmed later, as the chemistry they reported does not match that now known for ''hafnium''. After the war, in 1922, Coster and Hevesy found it by X-ray spectroscopic analysis in Norwegian zircon. [[Hafnium]] was thus the last stable element to be discovered, though rhenium was the last to be correctly recognized.

<gallery widths="165px" heights="165px">
File:Lutetium sublimed dendritic and 1cm3 cube.jpg|Lutetium, including a 1&nbsp;cm<sup>3</sup> cube
File:Rhenium single crystal bar and 1cm3 cube.jpg|Rhenium, including a 1&nbsp;cm<sup>3</sup> cube
File:Hf-crystal bar.jpg|Hafnium, in the form of a 1.7&nbsp;kg bar
</gallery>

By the end of World War II scientists had synthesized four post-uranium elements, all of which are radioactive (unstable) metals: neptunium (in 1940), plutonium (1940–41), and curium and americium (1944), representing elements 93 to 96. The first two of these were eventually found in nature as well. Curium and americium were by-products of the Manhattan project, which produced the world's first atomic bomb in 1945. The bomb was based on the nuclear fission of uranium, a metal first thought to have been discovered nearly 150 years earlier.

===Post-World War II developments===

====Superalloys====
{{Main|Superalloy}}

[[File:ریخته گري دقیق سوپرآلیاژهای نیکل.jpg|thumb|Heat treating superalloy turbine blades]]
Superalloys composed of combinations of Fe, Ni, Co, and Cr, and lesser amounts of W, Mo, Ta, Nb, Ti, and Al were developed shortly after World War II for use in high performance engines, operating at elevated temperatures (above 650&nbsp;°C (1,200&nbsp;°F)). They retain most of their strength under these conditions, for prolonged periods, and combine good low-temperature ductility with resistance to corrosion or oxidation. Superalloys can now be found in a wide range of applications including land, maritime, and aerospace turbines, and chemical and petroleum plants.

====Transcurium metals====
The successful development of the atomic bomb at the end of World War II sparked further efforts to synthesize new elements, nearly all of which are, or are expected to be, metals, and all of which are radioactive. It was not until 1949 that element 97 ([[Berkelium]]), next after element 96 ([[Curium]]), was synthesized by firing alpha particles at an americium target. In 1952, element 100 ([[Fermium]]) was found in the debris of the first hydrogen bomb explosion; hydrogen, a nonmetal, had been identified as an element nearly 200 years earlier. Since 1952, elements 101 ([[Mendelevium]]) to 118 ([[Oganesson]]) have been synthesized.

====Bulk metallic glasses====
{{Main|Metallic Glass}}
[[File:Metalic Glas Vitreloy4.jpg|thumb|Metallic Glass Vitreloy4]]

A metallic glass (also known as an amorphous or glassy metal) is a solid metallic material, usually an alloy, with a disordered atomic-scale structure. Most pure and alloyed metals, in their solid state, have atoms arranged in a highly ordered crystalline structure. In contrast these have a non-crystalline glass-like structure. But unlike common glasses, such as window glass, which are typically electrical insulators, amorphous metals have good electrical conductivity. Amorphous metals are produced in several ways, including extremely rapid cooling, physical vapor deposition, solid-state reaction, ion irradiation, and mechanical alloying. The first reported metallic glass was an alloy (Au<sub>75</sub>Si<sub>25</sub>) produced at [[Caltech]] in 1960. More recently, batches of amorphous steel with three times the strength of conventional steel alloys have been produced. Currently, the most important applications rely on the special magnetic properties of some ferromagnetic metallic glasses. The low magnetization loss is used in high-efficiency transformers. Theft control ID tags and other article surveillance schemes often use metallic glasses because of these magnetic properties.

====Shape-memory alloys====
{{Main|Shape-memory alloy}}
A shape-memory alloy (SMA) is an alloy that "remembers" its original shape and when deformed returns to its pre-deformed shape when heated. While the shape memory effect had been first observed in 1932, in an Au-Cd alloy, it was not until 1962, with the accidental discovery of the effect in a Ni-Ti alloy that research began in earnest, and another ten years before commercial applications emerged. SMA's have applications in robotics and automotive, aerospace, and biomedical industries. There is another type of SMA, called a ferromagnetic shape-memory alloy (FSMA), that changes shape under strong magnetic fields. These materials are of interest as the magnetic response tends to be faster and more efficient than temperature-induced responses.

====Quasicrystalline alloys====
{{Main|Quasicrystal}}
[[File:Ho-Mg-ZnQuasicrystal.jpg|thumb|A Ho-Mg-Zn icosahedral quasicrystal formed as a pentagonal [[dodecahedron]], the [[dual polyhedron|dual]] of the [[icosahedron]]|alt=A metallic regular dodecahedron]]
In 1984, Israeli metallurgist [[Dan Shechtman]] found an aluminium-manganese alloy having five-fold symmetry, in breach of crystallographic convention at the time which said that crystalline structures could only have two-, three-, four-, or six-fold symmetry. Due to reservation about the scientific community's reaction, it took Shechtman two years to publish the results&nbsp;for which he was awarded the Nobel Prize in Chemistry in 2011. Since this time, hundreds of quasicrystals have been reported and confirmed. They exist in many metallic alloys (and some polymers). Quasicrystals are found most often in aluminium alloys (Al-Li-Cu, Al-Mn-Si, Al-Ni-Co, Al-Pd-Mn, Al-Cu-Fe, Al-Cu-V, etc.), but numerous other compositions are also known (Cd-Yb, Ti-Zr-Ni, Zn-Mg-Ho, Zn-Mg-Sc, In-Ag-Yb, Pd-U-Si, etc.). [[Quasicrystal]]s effectively have infinitely large unit cells. [[Icosahedrite]] Al<sub>63</sub>Cu<sub>24</sub>Fe<sub>13</sub>, the first quasicrystal found in nature, was discovered in 2009. Most quasicrystals have ceramic-like properties including low electrical conductivity (approaching values seen in insulators) and low thermal conductivity, high hardness, brittleness, and resistance to corrosion, and non-stick properties. Quasicrystals have been used to develop heat insulation,&nbsp;LEDs, diesel engines, and new materials that convert heat to electricity. New applications may take advantage of the low coefficient of friction and the hardness of some quasicrystalline materials, for example embedding particles in plastic to make strong, hard-wearing, low-friction plastic gears. Other potential applications include selective solar absorbers for power conversion, broad-wavelength reflectors, and bone repair and prostheses applications where biocompatibility, low friction, and corrosion resistance are required.

====Complex metallic alloys====
{{Main|Complex metallic alloy}}
Complex metallic alloys (CMAs) are intermetallic compounds characterized by large unit cells comprising some tens up to thousands of atoms; the presence of well-defined clusters of atoms (frequently with icosahedral symmetry); and partial disorder within their crystalline lattices. They are composed of two or more metallic elements, sometimes with metalloids or [[chalcogenides]] added. They include, for example, NaCd2, with 348 sodium atoms and 768 cadmium atoms in the unit cell. [[Linus Pauling]] attempted to describe the structure of NaCd<sub>2</sub> in 1923, but did not succeed until 1955. At first called "giant unit cell crystals", interest in CMAs, as they came to be called, did not pick up until 2002, with the publication of a paper called "Structurally Complex Alloy Phases", given at the ''8th International Conference on Quasicrystals.'' Potential applications of CMAs include as heat insulation; solar heating; magnetic refrigerators; using waste heat to generate electricity; and coatings for turbine blades in military engines.

====High-entropy alloys====
{{Main|High-entropy alloy}}
High entropy alloys (HEAs) such as AlLiMgScTi are composed of equal or nearly equal quantities of five or more metals. Compared to conventional alloys with only one or two base metals, HEAs have considerably better strength-to-weight ratios, higher tensile strength, and greater resistance to fracturing, corrosion, and oxidation. Although HEAs were described as early as 1981, significant interest did not develop until the 2010s; they continue to be a focus of research in materials science and engineering because of their desirable properties.

====MAX phase====
{| class="wikitable plainrowheaders" style="float:right; margin-left:2em; margin-top:-2em;"
|+ MAX phase<br />alloy examples
!scope="col"| MAX
!scope="col"| M
!scope="col"| A
!scope="col"| X
|-
!scope="row"| Hf<sub>2</sub>SnC
| Hf || Sn || C
|-
!scope="row"| Ti<sub>4</sub>AlN<sub>3</sub>
| Ti || Al || N
|-
!scope="row"| Ti<sub>3</sub>SiC<sub>2</sub>
| Ti || Si || C
|-
!scope="row"| Ti<sub>2</sub>AlC
| Ti || Al || C
|-
!scope="row"| Cr<sub>2</sub>AlC<sub>2</sub>
| Cr || Al || C
|-
!scope="row"| Ti<sub>3</sub>AlC<sub>2</sub>
| Ti || Al || C
|}
{{Main|MAX phases}}
In a Max phase, '''M''' is an early transition metal, '''A''' is an A group element (mostly group IIIA and IVA, or groups 13 and 14), and '''X''' is either carbon or nitrogen. Examples are Hf<sub>2</sub>SnC and Ti<sub>4</sub>AlN<sub>3</sub>. Such alloys have high electrical and thermal conductivity, thermal shock resistance, damage tolerance, machinability, high elastic stiffness, and low thermal expansion coefficients.<ref>{{Cite journal |last1=Hanaor |first1=D.A.H. |last2=Hu |first2=L. |last3=Kan |first3=W.H. |last4=Proust |first4=G. |last5=Foley |first5=M. |last6=Karaman |first6=I. |last7=Radovic |first7=M. |date=2016 |title=Compressive performance and crack propagation in Al alloy/Ti2AlC composites |url=https://linkinghub.elsevier.com/retrieve/pii/S0921509316307419 |journal=Materials Science and Engineering: A |language=en |volume=672 |pages=247–256 |doi=10.1016/j.msea.2016.06.073|arxiv=1908.08757 }}</ref> They can be polished to a metallic luster because of their excellent electrical conductivities. During mechanical testing, it has been found that polycrystalline Ti<sub>3</sub>SiC<sub>2</sub> cylinders can be repeatedly compressed at room temperature, up to stresses of 1 GPa, and fully recover upon the removal of the load. Some MAX phases are also highly resistant to chemical attack (e.g. Ti<sub>3</sub>SiC<sub>2</sub>) and high-temperature oxidation in air (Ti<sub>2</sub>AlC, Cr<sub>2</sub>AlC<sub>2</sub>, and Ti<sub>3</sub>AlC<sub>2</sub>). Potential applications for MAX phase alloys include: as tough, machinable, thermal shock-resistant refractories; high-temperature heating elements; coatings for electrical contacts; and neutron irradiation resistant parts for nuclear applications.