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Adolf Martens
Adolf Martens (Adolf Karl Gottfried Martens), 6 March 1850 in Gammelin – 24 July 1914 in Groß-Lichterfelde, was a German metallurgist and the namesake of the steel structure 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 M ... and the martensitic transformation, a type of diffusionless phase transition in the solid state. He also made significant contributions to the field of tribology. The functional relationship between the coefficient of friction and the product of sliding speed and viscosity divided by the normal load (well known as the Stribeck curve) was experimentally explored by Adolf Martens in 1888, long before Richard Stribeck made his pioneering measurements in 1902. References External links * * German metallurgists Engineers from Mecklenburg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Büste Unter Den Eichen 87 (Lifel) Adolf Martens
Büste is a village and a former municipality in the district of Stendal, in Saxony-Anhalt, Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwee .... It has been a part of the town Bismark since 1 January 2010. Former municipalities in Saxony-Anhalt Bismark, Germany {{Stendal-geo-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gammelin
Gammelin is a municipality in the administrative Ludwigslust-Parchim district, in Mecklenburg-Vorpommern, Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwee .... The municipality is administered by the Ludwiglust district office of Hagenow Land which is situated in Hagenow. Gammelin is also administered in conjunction with the neighbouring village of Backendorf. Geography Gammelin is located between the town of Hagenow to the south and the state capital of Schwerin to the north. The A24 motorway (Bundesautobahn 24) runs south of the village approximately 2.5 kilometers away and the B321 main road (Bundesstraße 321) runs approximately 3 kilometers to the east. History Gammelin is first listed in a document from 1219 as Chemelin; the village church is mentioned in records as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Groß-Lichterfelde
Lichterfelde () is a locality in the borough of Steglitz-Zehlendorf in Berlin, Germany. Until 2001 it was part of the former borough of Steglitz, along with Steglitz and Lankwitz. Lichterfelde is home to institutions like the Berlin Botanical Garden and Museum, the German Federal Intelligence Service (BND), the German Federal Archives and the Charité university hospital's ''Benjamin Franklin Campus''. Many embassies and landmark-protected buildings are located in the affluent mansion settlement in Lichterfelde West. History The Prussian village ' was founded in the 13th century by Flemish settlers. It witnessed considerable growth in the 19th century when the two "villa colonies" of and were founded: two elegant settlements for wealthy Berliners consisting completely of villas or mansions. The settlements and the historical villages of ' and ' were united in 1880 under the name ' (Greater Lichterfelde). Lichterfelde was chosen as the seat of the Prussian Main Military acade ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metallurgist
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; that is, the way in which science is applied to 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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-resistant typically need an additional 11% chromium. Because of its high tensile strength and low cost, steel is used in buildings, infrastructure, tools, ships, trains, cars, machines, electrical appliances, weapons, and rockets. Iron is the base metal of steel. Depending on the temperature, it can take two crystalline forms (allotropic forms): body-centred cubic and face-centred cubic. The interaction of the allotropes of iron with the alloying elements, primarily carbon, gives steel and cast iron their range of unique properties. In pure iron, the crystal structure has relatively little resistance to the iron atoms slipping past one another, and so pure iron is quite ductile, or soft and easily formed. In steel, small amounts of ... [...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 In physical chemistry, supersaturation occurs with a solution when the concentration of a solute exceeds the concentration specified by the value of solubility at equilibrium. Most commonly the term is applied to a solution of a solid in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diffusionless Transformation
A diffusionless transformation is a phase change that occurs without the long-range diffusion of atoms but rather by some form of cooperative, homogenous movement of many atoms that results in a change in the crystal structure. These movements are small, usually less than the interatomic distances, and the neighbors of an atom remain close. The systematic movement of large numbers of atoms led to some to refer to these as ''military'' transformations in contrast to ''civilian'' diffusion-based phase changes, initially by Frederick Charles Frank and John Wyrill Christian. The most commonly encountered transformation of this type is the martensitic transformation which, while probably the most studied, is only one subset of non-diffusional transformations. The martensitic transformation in steel represents the most economically significant example of this category of phase transformations, but an increasing number of alternatives, such as shape memory alloys, are becoming more ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phase Transition
In chemistry, thermodynamics, and other related fields, a phase transition (or phase change) is the physical process of transition between one state of a medium and another. Commonly the term is used to refer to changes among the basic states of matter: solid, liquid, and gas, and in rare cases, plasma. A phase of a thermodynamic system and the states of matter have uniform physical properties. During a phase transition of a given medium, certain properties of the medium change as a result of the change of external conditions, such as temperature or pressure. This can be a discontinuous change; for example, a liquid may become gas upon heating to its boiling point, resulting in an abrupt change in volume. The identification of the external conditions at which a transformation occurs defines the phase transition point. Types of phase transition At the phase transition point for a substance, for instance the boiling point, the two phases involved - liquid and vapor, have ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tribology
Tribology is the science and engineering of interacting surfaces in relative motion. It includes the study and application of the principles of friction, lubrication and wear. Tribology is highly interdisciplinary, drawing on many academic fields, including physics, chemistry, materials science, mathematics, biology and engineering. People who work in the field of tribology are referred to as ''tribologists''. The fundamental objects of study in tribology are tribosystems, which are physical systems of contacting surfaces. In lubricated tribosystems, contact stress can create tribofilms. Subfields of tribology include biotribology, nanotribology, space tribology and tribotronics. Etymology The word ''tribology'' derives from the Greek root τριβ- of the verb , ''tribo'', "I rub" in classic Greek, and the suffix '' -logy'' from , '' -logia'' "study of", "knowledge of". Peter Jost coined the word in 1966, in the eponymous report which highlighted the cost of frictio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stribeck Curve
The Stribeck curve is a fundamental concept in the field of tribology. It shows that friction in fluid-lubricated contacts is a non-linear function of the contact load, the lubricant viscosity and the lubricant entrainment speed. The discovery and underlying research is usually attributed to Richard StribeckStribeck, R. (1901), Kugellager für beliebige Belastungen (Ball Bearings for any Stress), Zeitschrift des Vereins Deutscher Ingenieure 45.Stribeck, R. (1902), Die wesentlichen Eigenschaften der Gleit- und Rollenlager (Characteristics of Plain and Roller Bearings), Zeit. des VDI 46. and Mayo D. Hersey, who studied friction in journal bearings for railway wagon applications during the first half of the 20th century; however, other researchers have arrived at similar conclusions before. The mechanisms along the Stribeck curve have been understood today also on the atomistic level. Concept For a contact of two fluid-lubricated surfaces, the Stribeck curve shows the relationsh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Richard Stribeck
Richard Stribeck (7. July 1861 in Stuttgart , † 29. March 1950) was a German engineer, after whom the Stribeck Curve is named. Life Stribeck studied mechanical engineering in 1880 at the Technical University of Stuttgart in 1885 and worked as a designer in Königsberg. In 1888 he became professor in Stuttgart, and 1890 Professor of Mechanical Engineering at the Technical University of Darmstadt. 1893 he took a professorship at the Dresden Technical University. In 1896 he became head of the laboratory equipment of the university. In 1898 was head of the Stribeck Physical metallurgy department of the Technical Institute and director of the center for scientific and technical studies in Neubabelsberg. In 1902 he described the friction coefficient in lubricated bearings, now known as the Stribeck curve. From 1908 Stribeck worked for the Friedrich Krupp AG in Essen in 1919 at the Robert Bosch GmbH in Stuttgart. Stribeck was a college friend of the industrialist Robert Bosch, wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
German Metallurgists
German(s) may refer to: * Germany (of or related to) **Germania (historical use) * Germans, citizens of Germany, people of German ancestry, or native speakers of the German language ** For citizens of Germany, see also German nationality law **Germanic peoples (Roman times) * German language **any of the Germanic languages * German cuisine, traditional foods of Germany People * German (given name) * German (surname) * Germán, a Spanish name Places * German (parish), Isle of Man * German, Albania, or Gërmej * German, Bulgaria * German, Iran * German, North Macedonia * German, New York, U.S. * Agios Germanos, Greece Other uses * German (mythology), a South Slavic mythological being * Germans (band), a Canadian rock band * German (song), "German" (song), a 2019 song by No Money Enterprise * ''The German'', a 2008 short film * "The Germans", an episode of ''Fawlty Towers'' * ''The German'', a nickname for Congolese rebel André Kisase Ngandu See also * Germanic (disambi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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