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Anti-phase Domain
An antiphase domain (APD) is a type of planar crystallographic defect in which the atoms within a region of a crystal are configured in the opposite order to those in the perfect lattice system. Throughout the entire APD, atoms sit on the sites typically occupied by atoms of a different species. For example, in an ordered AB alloy, if an A atom occupies the site usually occupied by a B atom, a type of crystallographic point defect called an antisite defect is formed. If an entire region of the crystal is translated such that every atom in a region of the plane of atoms sits on its antisite, an antiphase domain is formed. In other words, an APD is a region formed from antisite defects of a parent lattice. On either side of this domain, the lattice is still perfect, and the boundaries of the domain are referred to as antiphase boundaries. Crucially, crystals on either side of an antiphase boundary are related by a translation, rather than a reflection (a crystal twin) or an inversion ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crystallographic Defect
A crystallographic defect is an interruption of the regular patterns of arrangement of atoms or molecules in crystalline solids. The positions and orientations of particles, which are repeating at fixed distances determined by the unit cell parameters in crystals, exhibit a periodic crystal structure, but this is usually imperfect.Ehrhart, P. (1991Properties and interactions of atomic defects in metals and alloys, volume 25 of Landolt-Börnstein, New Series III, chapter 2, p. 88, Springer, Berlin Several types of defects are often characterized: point defects, line defects, planar defects, bulk defects. Topological homotopy establishes a mathematical method of characterization. Point defects Point defects are defects that occur only at or around a single lattice point. They are not extended in space in any dimension. Strict limits for how small a point defect is are generally not defined explicitly. However, these defects typically involve at most a few extra or missing atoms. La ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Superalloy
A superalloy, or high-performance alloy, is an alloy with the ability to operate at a high fraction of its melting point. Several key characteristics of a superalloy are excellent mechanical strength, resistance to thermal creep deformation, good surface stability, and resistance to corrosion or oxidation. The crystal structure is typically face-centered cubic (FCC) austenitic. Examples of such alloys are Hastelloy, Inconel, Waspaloy, Rene alloys, Incoloy, MP98T, TMS alloys, and CMSX single crystal alloys. Superalloy development has relied heavily on both chemical and process innovations. Superalloys develop high temperature strength through solid solution strengthening and precipitation strengthening from secondary phase precipitates such as gamma prime and carbides. Oxidation or corrosion resistance is provided by elements such as aluminium and chromium. Superalloys are often cast as a single crystal—while grain boundaries may provide strength at low temperatures, th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diagram
A diagram is a symbolic representation of information using visualization techniques. Diagrams have been used since prehistoric times on walls of caves, but became more prevalent during the Enlightenment. Sometimes, the technique uses a three-dimensional visualization which is then projected onto a two-dimensional surface. The word ''graph'' is sometimes used as a synonym for diagram. Overview The term "diagram" in its commonly used sense can have a general or specific meaning: * ''visual information device'' : Like the term " illustration", "diagram" is used as a collective term standing for the whole class of technical genres, including graphs, technical drawings and tables. * ''specific kind of visual display'' : This is the genre that shows qualitative data with shapes that are connected by lines, arrows, or other visual links. In science the term is used in both ways. For example, Anderson (1997) stated more generally: "diagrams are pictorial, yet abstract, represen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Courtney Shearing
Courtney is a name of Old French origin, introduced into England after the Norman Conquest of 1066. It has two quite distinct interpretations: firstly, the surname may be locational, from places called Courtenay in the regions of Loiret and Gâtinais. The House of Courtenay was a significant French family with close association with both the French, and thereby, English royal lines; in England the Courtenays were Earls of Devon. Secondly, in some cases, bearers of the surname may be of Irish descent, since Courtney is also an Anglicized form of the Gaelic "O'Curnain", descendant of Curnan, from an Old Irish personal name of obscure origins. Recordings of the name from London Church Registers include: the christening of Thomas Courtney at All Hallows, London Wall, on 11 November 1569, and the marriage of William Courtney and Mary Lucas on 22 March 1590, at St Dunstan's, Stepney. John Courtney and his wife, Sybill, were early immigrants to America, leaving London on the ''Paule'' i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apb Courtney
APB may refer to: Law enforcement and military *All-points bulletin, a broadcast (about a wanted suspect or missing person) issued from one US law enforcement agency to another *Acquisition Program Baseline, in the United States military Media *"A.P.B.", a song on Womack & Womack's 1984 album ''Love Wars'' * APB (band), a Scottish band *Apoptygma Berzerk, a Norwegian electronic music group * ''APB'' (1987 video game) *'' APB: All Points Bulletin'', a 2010 massively multiplayer online game for Microsoft Windows * ''APB'' (TV series), an American television series that aired in 2017 Organizations *Accounting Principles Board, the former authoritative body of the American Institute of Certified Public Accountants *Alliance for Brazil *Asia Pacific Breweries Heineken Asia Pacific, formerly Asia Pacific Breweries (APB) is a Singaporean brewery company. Founded in 1931 as a joint venture between Heineken International and Fraser and Neave, it was renamed Asia Pacific Breweries (APB) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Precipitation 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 and stainless steels. 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 solids can produce many differen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dislocation
In materials science, a dislocation or Taylor's dislocation is a linear crystallographic defect or irregularity within a crystal structure that contains an abrupt change in the arrangement of atoms. The movement of dislocations allow atoms to slide over each other at low stress levels and is known as ''glide'' or slip. The crystalline order is restored on either side of a ''glide dislocation'' but the atoms on one side have moved by one position. The crystalline order is not fully restored with a ''partial dislocation''. A dislocation defines the boundary between ''slipped'' and ''unslipped'' regions of material and as a result, must either form a complete loop, intersect other dislocations or defects, or extend to the edges of the crystal. A dislocation can be characterised by the distance and direction of movement it causes to atoms which is defined by the Burgers vector. Plastic deformation of a material occurs by the creation and movement of many dislocations. The number and a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Courtney Antiphase Boundary
Courtney is a name of Old French origin, introduced into England after the Norman Conquest of 1066. It has two quite distinct interpretations: firstly, the surname may be locational, from places called Courtenay in the regions of Loiret and Gâtinais. The House of Courtenay was a significant French family with close association with both the French, and thereby, English royal lines; in England the Courtenays were Earls of Devon. Secondly, in some cases, bearers of the surname may be of Irish descent, since Courtney is also an Anglicized form of the Gaelic "O'Curnain", descendant of Curnan, from an Old Irish personal name of obscure origins. Recordings of the name from London Church Registers include: the christening of Thomas Courtney at All Hallows, London Wall, on 11 November 1569, and the marriage of William Courtney and Mary Lucas on 22 March 1590, at St Dunstan's, Stepney. John Courtney and his wife, Sybill, were early immigrants to America, leaving London on the ''Paule'' i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crystal System
In crystallography, a crystal system is a set of point groups (a group of geometric symmetries with at least one fixed point). A lattice system is a set of Bravais lattices. Space groups are classified into crystal systems according to their point groups, and into lattice systems according to their Bravais lattices. Crystal systems that have space groups assigned to a common lattice system are combined into a crystal family. The seven crystal systems are triclinic, monoclinic, orthorhombic, tetragonal, trigonal, hexagonal, and cubic. Informally, two crystals are in the same crystal system if they have similar symmetries (albeit there are many exceptions). Classifications Crystals can be classified in three ways: lattice systems, crystal systems and crystal families. The various classifications are often confused: in particular the trigonal crystal system is often confused with the rhombohedral lattice system, and the term "crystal system" is sometimes used to mean "latti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cai Apb
Cai or CAI may refer to: Places * Cai (state), a state in ancient China * Caí River, Rio Grande do Sul, Brazil * Cái River, Vietnam * Cairo International Airport (IATA airport code) * Caithness, a historic county in Scotland (Chapman code) Organisations * Canadian Airlines International, a defunct Canadian airline * Capitol Archaeological Institute, an American archaeological research and education institute part of The George Washington University * Central Asia Institute, a non-profit organization that promotes education in Central Asia * Chartered Accountants Ireland, Ireland's largest accountancy body * Christian Assemblies International, an Australian-based charity organisation and religious group * Club Alpino Italiano, the Italian alpine club * Coleraine Academical Institution, a school in Northern Ireland * College of Anaesthesiologists of Ireland, a medical training body in Ireland * Community Associations Institute, an influential trade association and special intere ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Partial Dislocation
In materials science, a partial dislocation is a decomposed form of dislocation that occurs within a crystalline material. An ''extended dislocation'' is a dislocation that has dissociated into a pair of partial dislocations. The vector sum of the Burgers vectors of the partial dislocations is the Burgers vector of the extended dislocation. Reaction favorability A dislocation will decompose into partial dislocations if the energy state of the sum of the partials is less than the energy state of the original dislocation. This is summarized by ''Frank's Energy Criterion'': : \begin , \boldsymbol, ^2>&, \boldsymbol, ^2+, \boldsymbol, ^2 \text\\ , \boldsymbol, ^2& , \frac \sqrt, ^2+, \frac \sqrt, ^2\\ \frac >& \frac+\frac \end The components of the ''Shockley Partials'' must add up to the original vector that is being decomposed: : \begin \frac (1) =& \frac(2)+\frac(1)\\ \frac (0) =& \frac(-1)+\frac(1)\\ \frac (-1) =& \frac(-1)+\frac(-2) \end Frank partial dislocations ''Frank ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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