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Physical Metallurgy
Physical metallurgy is one of the two main branches of the scientific approach to metallurgy, which considers in a systematic way the physical properties of metals and alloys. It is basically the fundamentals and applications of the theory of phase transformations in metal and alloys. While chemical metallurgy involves the domain of reduction/oxidation of metals, physical metallurgy deals mainly with mechanical and magnetic/electric/thermal properties of metals – as described by solid-state physics. Early history Timeline: * 1831 – Pavel Petrovich Anosov looks at metals in a microscope. * 1841 – Anosov finds the secret to Damascus steel. * 1868 – Dmitry Chernov founds physical metallurgy. He identifies the critical points of steel. * 1875 – William Chandler Roberts-Austen provides the diagram Ag-Cu. * 1878 – Adolf Martens describes relations between microstructure and physical properties, specially the role of kinks, defects and crystallization. * 188 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metallurgy
Metallurgy is a domain of materials science and engineering that studies the physical and chemical behavior of metallic elements, their inter-metallic compounds, and their mixtures, which are known as alloys. Metallurgy encompasses both the science and the technology of metals, including the production of metals and the engineering of metal components used in products for both consumers and manufacturers. Metallurgy is distinct from the craft of metalworking. Metalworking relies on metallurgy in a similar manner to how medicine relies on medical science for technical advancement. A specialist practitioner of metallurgy is known as a metallurgist. The science of metallurgy is further subdivided into two broad categories: chemical metallurgy and physical metallurgy. Chemical metallurgy is chiefly concerned with the reduction and oxidation of metals, and the chemical performance of metals. Subjects of study in chemical metallurgy include mineral processing, the extraction ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Austenite
Austenite, also known as gamma-phase iron (γ-Fe), is a metallic, non-magnetic allotrope of iron or a solid solution of iron with an alloying element. In plain-carbon steel, austenite exists above the critical eutectoid temperature of 1000 K (727 °C); other alloys of steel have different eutectoid temperatures. The austenite allotrope is named after Sir William Chandler Roberts-Austen (1843–1902). It exists at room temperature in some stainless steels due to the presence of nickel stabilizing the austenite at lower temperatures. Allotrope of iron From alpha iron undergoes a phase transition from body-centered cubic (BCC) to the face-centered cubic (FCC) configuration of gamma iron, also called austenite. This is similarly soft and ductile but can dissolve considerably more carbon (as much as 2.03% by mass at ). This gamma form of iron is present in the most commonly used type of stainless steel for making hospital and food-service equipment. Material Austenitiz ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kirkendall Effect
The Kirkendall effect is the motion of the interface between two metals that occurs due to the difference in diffusion rates of the metal atoms. The effect can be observed, for example, by placing insoluble markers at the interface between a pure metal and an alloy containing that metal, and heating to a temperature where atomic diffusion is reasonable for the given timescale; the boundary will move relative to the markers. This process was named after Ernest Kirkendall (1914–2005), assistant professor of chemical engineering at Wayne State University from 1941 to 1946. The paper describing the discovery of the effect was published in 1947. The Kirkendall effect has important practical consequences. One of these is the prevention or suppression of voids formed at the boundary interface in various kinds of alloy-to-metal bonding. These are referred to as Kirkendall voids. History The Kirkendall effect was discovered by Ernest Kirkendall and Alice Smigelskas in 1947, in the cours ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ernest Kirkendall
Ernest Oliver Kirkendall (July 6, 1914 – August 22, 2005) was an American chemist and metallurgist. He is known for his 1947 discovery of the Kirkendall effect. Life and works He was raised in Highland Park, Michigan and received his bachelor's from Wayne State University. His master's and PhD came from the University of Michigan, but he returned to Wayne to teach chemical engineering. In 1984 he was inducted into the College of Engineering's Hall of Fame. He died in a nursing home in Alexandria, Virginia Alexandria is an independent city (United States), independent city in Northern Virginia, United States. It lies on the western bank of the Potomac River approximately south of Washington, D.C., D.C. The city's population of 159,467 at the 2020 .... References Further reading * American metallurgists Wayne State University alumni University of Michigan alumni Wayne State University faculty 1914 births 2005 deaths People from Charlevoix County, Michigan People ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
George Sachs
George Sachs (April 5, 1896 – October 30, 1960) was a Russian-born German and American metallurgist. Born in Moscow, he taught at Frankfurt University (1930-1935), and the Case Institute of Technology (now Case Western Reserve University, ''CWRU''; him since 1942) He was of Jewish birth, and left Germany with his family in 1937 to escape Nazi persecution, and settled in the United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 .... He was the father of the astronomer Rainer K. Sachs. He is known for his work on Kurdyumov–Sachs orientations with Georgy Kurdyumov. Works * '' Praktische Metallkunde'', 1933 * * * * * * External links * * 1896 births 1960 deaths Scientists from Moscow German metallurgists 20th-century German chemists 20th-century American ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Georgy Kurdyumov
Georgy Vyacheslavovich Kurdyumov (; 14 February 1902 – 6 July 1996) was a Soviet metallurgist and physicist. He went on to become one of the most famous metallurgist of his time in the Soviet Union. When the Institute of Solid State Physics was established on February 15, 1963, he was one of the main organizers of the institute. Early days Georgy Kurdyumov was born on February 14, 1902, in Rylsk. His father was a priest. He trained as a physicist at the Ioffe Institute in Saint Petersburg. As a young scientist, he took interest in metallurgy and after obtaining his diploma, he was one of the 220 Soviet Union scientists who were allowed to spend time abroad. He went to Germany, and worked with George Sachs in Berlin. Their collaboration resulted in Kurdyumov-Sachs (K-S) orientation. Career After he moved back to the Soviet Union, he went to Ukraine and became one of the founders of the Dnepropetrovsk Physico-Technical Institute in Dnipropetrovsk. He was appointed director o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Martensite
Martensite is a very hard form of steel crystalline structure. It is named after German metallurgist Adolf Martens. By analogy the term can also refer to any crystal structure that is formed by diffusionless transformation. Properties Martensite is formed in carbon steels by the rapid cooling ( quenching) of the austenite form of iron at such a high rate that carbon atoms do not have time to diffuse out of the crystal structure in large enough quantities to form cementite (Fe3C). Austenite is gamma-phase iron (γ-Fe), a solid solution of iron and alloying elements. As a result of the quenching, the face-centered cubic austenite transforms to a highly strained body-centered tetragonal form called martensite that is supersaturated with carbon. The shear deformations that result produce a large number of dislocations, which is a primary strengthening mechanism of steels. The highest hardness of a pearlitic steel is 400 Brinell, whereas martensite can achieve 700&n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Superlattice
A superlattice is a periodic structure of layers of two (or more) materials. Typically, the thickness of one layer is several nanometers. It can also refer to a lower-dimensional structure such as an array of quantum dots or quantum wells. Discovery Superlattices were discovered early in 1925 by Johansson and Linde after the studies on gold–copper and palladium–copper systems through their special X-ray diffraction patterns. Further experimental observations and theoretical modifications on the field were done by Bradley and Jay, Gorsky, Borelius, Dehlinger and Graf, Bragg and Williams and Bethe. Theories were based on the transition of arrangement of atoms in crystal lattices from disordered state to an ordered state. Mechanical properties J.S. Koehler theoretically predicted that by using alternate (nano-)layers of materials with high and low elastic constants, shearing resistance is improved by up to 100 times as the Frank–Read Source, Frank–Read source of dislo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edgar Bain
Edgar Collins Bain (September 14, 1891 – November 27, 1971) was an American metallurgist and member of the National Academy of Sciences, who worked for the US Steel Corporation of Pittsburgh, Pennsylvania. He worked on the alloying and heat treatment of steel; Bainite is named in his honor. He was born near LaRue, Ohio to Milton Henry (of Scottish descent) and Alice Anne Collins Bain. He graduated with a B.S. from Ohio State University in 1912. He received his M.S. in 1916 and his Ph.D. in 1919 both from Ohio State. His written works include ''Functions of the Alloying Elements in Steel'', published by ASM International. He died on November 27, 1971, in Edgeworth, Pennsylvania. He was elected in 1923 a Fellow of the American Physical Society The American Physical Society (APS) is a not-for-profit membership organization of professionals in physics and related disciplines, comprising nearly fifty divisions, sections, and other units. Its mission is the advancement and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Order-disorder Transition
In physics, the terms order and disorder designate the presence or absence of some symmetry or correlation in a many-particle system. In condensed matter physics, systems typically are ordered at low temperatures; upon heating, they undergo one or several phase transitions into less ordered states. Examples for such an order-disorder transition are: * the melting of ice: solid–liquid transition, loss of crystalline order; * the demagnetization of iron by heating above the Curie temperature: ferromagnetic–paramagnetic transition, loss of magnetic order. The degree of freedom that is ordered or disordered can be translational (crystalline ordering), rotational (ferroelectric ordering), or a spin state (magnetic ordering). The order can consist either in a full crystalline space group symmetry, or in a correlation. Depending on how the correlations decay with distance, one speaks of long range order or short range order. If a disordered state is not in thermodynamic equilib ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gustav Heinrich Tammann
Gustav Heinrich Johann Apollon Tammann ( – 17 December 1938) was a prominent Baltic German chemist-physicist who made important contributions in the fields of glassy and solid solutions, heterogeneous equilibria, crystallization, and metallurgy. He first predicted the order-disorder transition in alloys. Biography Tammann was born in Yamburg (now Kingisepp, Leningrad Oblast). His father, Heinrich Tammann (1833–1864) was of Estonian peasant origin and his mother, Matilda Schünmann, was of German origin. Tammann graduated from University of Dorpat in chemistry. He went to Göttingen University in 1903 where he established the first Institute of Inorganic Chemistry in Germany. In 1908 he was appointed director of the Physico-Chemical Institute. Tammann died in Göttingen at age 77. Research In 1900, he discovered the phases of ice, now known as ice II and ice III. Later, his interests focused on the physics and physical chemistry of metals and alloys (metallurgy). He ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Age Hardening
Precipitation hardening, also called age hardening or particle hardening, is a heat treatment technique used to increase the yield strength of malleable materials, including most structural alloys of aluminium, magnesium, nickel, titanium, and some steels, stainless steels, and duplex stainless steel. In superalloys, it is known to cause yield strength anomaly providing excellent high-temperature strength. Precipitation hardening relies on changes in solid solubility with temperature to produce fine particles of an impurity phase, which impede the movement of dislocations, or defects in a crystal's lattice. Since dislocations are often the dominant carriers of plasticity, this serves to harden the material. The impurities play the same role as the particle substances in particle-reinforced composite materials. Just as the formation of ice in air can produce clouds, snow, or hail, depending upon the thermal history of a given portion of the atmosphere, precipitation in soli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
