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In master data management (MDM), the golden copy refers to the master data (master version) of the reference data which works as an authoritative source for the "truth" for all applications in a given IT landscape.
Wikipedia - Golden record (informatics) - Master data
In master locksmithing, key relevance is the measurable difference between an original key and a copy made of that key, either from a wax impression or directly from the original, and how similar the two keys are in size and shape. It can also refer to the measurable difference between a key and the size required to fi...
Wikipedia - Key relevance - Summary
In all machining work, there are measurable amounts of difference between the design specification of an object, and its actual manufactured size. In locksmithing, the allowable tolerance is decided by the range of minute differences between a key's size and shape in comparison to the size and shape required to turn th...
Wikipedia - Key relevance - Summary
Key relevance is the measure of similarity between the key and the optimal size needed to fit the lock, or it is the similarity between a duplicate key and the original it is seeking to replicate. Key relevance cannot be deduced from a key code, since the key code merely refers to a central authoritative source for des...
Wikipedia - Key relevance - Summary
In match play the stroke index is used to evenly spread the handicap allowances across the course. This is done by allocating the odd stroke index numbers to the more difficult half (9 holes, Out or In) of the course, which is usually the longer half, and the even stroke index numbers to the easier half of the course. ...
Wikipedia - Stroke Index - Detail
The 7th to the 10th stroke index holes should be allocated so that a player receiving 10 strokes does not receive strokes on three consecutive holes.In Stableford, par and bogey competitions using stroke play, where an even distribution of strokes is not so important, if the club uses a different stroke index for these...
Wikipedia - Stroke Index - Detail
For example, a player with a handicap of 12 would be given a stroke deduction only on the holes with stroke index 1 to 12. A player with a handicap of 24 would receive a stroke at all 18 holes plus an extra stroke at holes 1 to 6 (18 + 6 = 24) so they would receive two strokes on holes 1 to 6 and one stroke for holes 7...
Wikipedia - Stroke Index - Detail
In a handicap match play competition where the one player has a handicap 8 shots higher than their opponent then that player will receive a handicap stroke on the holes with stroke index 1 to 8. The stroke index is usually printed on a golf club's scorecard listed alongside each hole. == References ==
Wikipedia - Stroke Index - Detail
In matches organized by the International Practical Shooting Confederation, both steel and paper targets are used. Currently the only paper targets used for handgun is the IPSC Target (formerly Classic Target) and the 2/3 scaled down IPSC Mini Target (formerly IPSC Mini Classic Target). The center of these paper target...
Wikipedia - Shooting target - International Practical Shooting Confederation
In matches where Duckworth-Lewis revised targets are set due to interruptions which reduce the number of overs bowled, those revised targets and revised overs are used to calculate the NRR for both teams. For example, Team A are dismissed for 165 in 33.5 overs. Team B progresses to 120–0, but play is halted after 18 ov...
Wikipedia - Net Run Rate - 7. Interrupted game with revised D/L target
Because the target was revised to 150 runs from 44 overs, Team A's total is reset to 149 from 44 overs, thus their RR = 149 44 ≈ 3.39 {\displaystyle ={\frac {149}{44}}\approx 3.39} . Team B's RR, however, is computed as normal: 150 26.33 ≈ 5.70 {\displaystyle {\frac {150}{26.33}}\approx 5.70} . Computing the match NRR ...
Wikipedia - Net Run Rate - 7. Interrupted game with revised D/L target
In material science and solid mechanics, orthotropic materials have material properties at a particular point which differ along three orthogonal axes, where each axis has twofold rotational symmetry. These directional differences in strength can be quantified with Hankinson's equation. They are a subset of anisotropic...
Wikipedia - Orthotropic material - Summary
A familiar example of an orthotropic material is wood. In wood, one can define three mutually perpendicular directions at each point in which the properties are different. It is most stiff (and strong) along the grain (axial direction), because most cellulose fibrils are aligned that way.
Wikipedia - Orthotropic material - Summary
It is usually least stiff in the radial direction (between the growth rings), and is intermediate in the circumferential direction. This anisotropy was provided by evolution, as it best enables the tree to remain upright.
Wikipedia - Orthotropic material - Summary
Because the preferred coordinate system is cylindrical-polar, this type of orthotropy is also called polar orthotropy. Another example of an orthotropic material is sheet metal formed by squeezing thick sections of metal between heavy rollers.
Wikipedia - Orthotropic material - Summary
This flattens and stretches its grain structure. As a result, the material becomes anisotropic — its properties differ between the direction it was rolled in and each of the two transverse directions. This method is used to advantage in structural steel beams, and in aluminium aircraft skins.
Wikipedia - Orthotropic material - Summary
If orthotropic properties vary between points inside an object, it possesses both orthotropy and inhomogeneity. This suggests that orthotropy is the property of a point within an object rather than for the object as a whole (unless the object is homogeneous). The associated planes of symmetry are also defined for a sma...
Wikipedia - Orthotropic material - Summary
Orthotropic materials are a subset of anisotropic materials; their properties depend on the direction in which they are measured. Orthotropic materials have three planes/axes of symmetry. An isotropic material, in contrast, has the same properties in every direction.
Wikipedia - Orthotropic material - Summary
It can be proved that a material having two planes of symmetry must have a third one. Isotropic materials have an infinite number of planes of symmetry. Transversely isotropic materials are special orthotropic materials that have one axis of symmetry (any other pair of axes that are perpendicular to the main one and or...
Wikipedia - Orthotropic material - Summary
One common example of transversely isotropic material with one axis of symmetry is a polymer reinforced by parallel glass or graphite fibers. The strength and stiffness of such a composite material will usually be greater in a direction parallel to the fibers than in the transverse direction, and the thickness directio...
Wikipedia - Orthotropic material - Summary
Orthotropic material properties have been shown to provide a more accurate representation of bone's elastic symmetry and can also give information about the three-dimensional directionality of bone's tissue-level material properties.It is important to keep in mind that a material which is anisotropic on one length scal...
Wikipedia - Orthotropic material - Summary
In material science glutaraldehyde application areas range from polymers to metals and biomaterials. Glutaraldehyde is commonly used as fixing agent before characterization of biomaterials for microscopy. Glutaraldehyde is a powerful crosslinking agent for many polymers containing primary amine groups.. Glutaraldehdye ...
Wikipedia - Glutaraldehyde - Material Science
In material science, layered materials are solids with highly anisotropic bonding, in which two-dimensional sheets are internally strongly bonded, but only weakly bonded to adjacent layers. Owing to their distinctive structures, layered materials are often suitable for intercalation reactions.One large family of layere...
Wikipedia - Layered materials - Summary
In material science, resilience is the ability of a material to absorb energy when it is deformed elastically, and release that energy upon unloading. Proof resilience is defined as the maximum energy that can be absorbed up to the elastic limit, without creating a permanent distortion. The modulus of resilience is def...
Wikipedia - Resilience (materials science) - Summary
It can be calculated by integrating the stress–strain curve from zero to the elastic limit. In uniaxial tension, under the assumptions of linear elasticity, U r = σ y 2 2 E = σ y ε y 2 {\displaystyle U_{r}={\frac {\sigma _{y}^{2}}{2E}}={\frac {\sigma _{y}\varepsilon _{y}}{2}}} where Ur is the modulus of resilience, σy ...
Wikipedia - Resilience (materials science) - Summary
In material selection it is important to look at the interaction between the matrix and the secondary phase. For example, crosslinking within the rubber phase promotes high strength fibril formation that toughens the rubber, preventing particle fracture.Carboxyl-terminated butadiene-acrylonitrile (CTBN) is often used t...
Wikipedia - Rubber toughening - Rubber selection and miscibility with continuous phase
To do so it is important to match refractive indices of both phases. Traditional rubber particles do not offer this quality. Modifying the surface of nanoparticles with polymers of comparable refractive indices is an interest of current research.
Wikipedia - Rubber toughening - Rubber selection and miscibility with continuous phase
In materials and electric battery research, cobalt oxide nanoparticles usually refers to particles of cobalt(II,III) oxide Co3O4 of nanometer size, with various shapes and crystal structures. Cobalt oxide nanoparticles have potential applications in lithium-ion batteries and electronic gas sensors.
Wikipedia - Cobalt oxide nanoparticles - Summary
In materials chemistry, a binary phase or binary compound is a chemical compound containing two different elements. Some binary phase compounds are molecular, e.g. carbon tetrachloride (CCl4). More typically binary phase refers to extended solids. Famous examples zinc sulfide, which contains zinc and sulfur, and tungst...
Wikipedia - Binary phase - Summary
In materials chemistry, a quaternary phase is a chemical compound containing four elements. Some compounds can be molecular or ionic, examples being chlorodifluoromethane (CHClF2) sodium bicarbonate (NaCO3H). More typically quaternary phase refers to extended solids. A famous example are the yttrium barium copper oxide...
Wikipedia - Quaternary phase - Summary
In materials engineering and metallurgy, hot hardness or red hardness (when a metal glows a dull red from the heat) corresponds to hardness of a material at high temperatures. As the temperature of the material increases, hardness decreases and at some point a drastic change in hardness occurs. The hardness at this poi...
Wikipedia - Hot hardness - Summary
In materials engineering, suspension plasma spray (SPS) is a form of plasma spraying where the ceramic feedstock is dispersed in a liquid suspension before being injected into the plasma jet.By suspending powder in a fluid, normal feeding problems are circumvented, allowing the deposition of finer microstructures throu...
Wikipedia - Suspension Plasma Spray - Summary
In materials management, ABC analysis is an inventory categorisation technique. ABC analysis divides an inventory into three categories—"A items" with very tight control and accurate records, "B items" with less tightly controlled and good records, and "C items" with the simplest controls possible and minimal records. ...
Wikipedia - ABC analysis - Summary
Thus, the inventory is grouped into three categories (A, B, and C) in order of their estimated importance. 'A' items are very important for an organization.
Wikipedia - ABC analysis - Summary
Because of the high value of these 'A' items, frequent value analysis is required. In addition to that, an organization needs to choose an appropriate order pattern (e.g. 'just-in-time') to avoid excess capacity. 'B' items are important, but of course less important than 'A' items and more important than 'C' items. The...
Wikipedia - ABC analysis - Summary
In materials modeled by linear elastic fracture mechanics (LEFM), crack extension occurs when the applied energy release rate G {\displaystyle G} exceeds G R {\displaystyle G_{R}} , where G R {\displaystyle G_{R}} is the material's resistance to crack extension. Conceptually G {\displaystyle G} can be thought of as the...
Wikipedia - Crack growth resistance curve - Summary
A complication to this process is that in some materials, G R {\displaystyle G_{R}} is not a constant value during the crack extension process. A plot of crack growth resistance G R {\displaystyle G_{R}} versus crack extension Δ a {\displaystyle \Delta a} is called a crack growth resistance curve, or R-curve. A plot of...
Wikipedia - Crack growth resistance curve - Summary
The nature of the applied driving force curve relative to the material's R-curve determines the stability of a given crack. The usage of R-curves in fracture analysis is a more complex, but more comprehensive failure criteria compared to the common failure criteria that fracture occurs when G ≥ G c {\displaystyle G\geq...
Wikipedia - Crack growth resistance curve - Summary
In materials of high atomic number (e.g. tungsten, uranium, plutonium) the electrons of energies >~10 MeV predominantly lose energy by bremsstrahlung, and high-energy photons by e+e− pair production. The characteristic amount of matter traversed for these related interactions is called the radiation length X0, usually ...
Wikipedia - Radiation length - Definition
The radiation length for a given material consisting of a single type of nucleus can be approximated by the following expression: where Z is the atomic number and A is mass number of the nucleus. For Z > 4, a good approximation is where na is the number density of the nucleus, ℏ {\displaystyle \hbar } denotes the reduc...
Wikipedia - Radiation length - Definition
In materials processing a grinder is a machine for producing fine particle size reduction through attrition and compressive forces at the grain size level. See also crusher for mechanisms producing larger particles. In general, grinding processes require a relatively large amount of energy; for this reason, an experime...
Wikipedia - Rod mill - Grinding machines
In materials science (specifically crystallography), cocrystals are "solids that are crystalline, single-phase materials composed of two or more different molecular or ionic compounds generally in a stoichiometric ratio which are neither solvates nor simple salts." A broader definition is that cocrystals "consist of tw...
Wikipedia - Cocrystal - Summary
In materials science Functionally Graded Materials (FGMs) may be characterized by the variation in composition and structure gradually over volume, resulting in corresponding changes in the properties of the material. The materials can be designed for specific function and applications. Various approaches based on the ...
Wikipedia - Functionally graded material - Summary
In materials science Giant Magnetoimpedance (GMI) is the effect that occurs in some materials where an external magnetic field causes a large variation in the electrical impedance of the material. It should not be confused with the separate physical phenomenon of Giant Magnetoresistance.
Wikipedia - Giant magnetoimpedance - Summary
In materials science and colloidal chemistry, the term colloidal particle refers to a small amount of matter having a size typical for colloids and with a clear phase boundary. The dispersed-phase particles have a diameter between approximately 1 and 1000 nanometers. Colloids are heterogeneous in nature, invisible to t...
Wikipedia - Particle size - Colloidal particle
In materials science and continuum mechanics, viscoelasticity is the property of materials that exhibit both viscous and elastic characteristics when undergoing deformation. Viscous materials, like water, resist shear flow and strain linearly with time when a stress is applied. Elastic materials strain when stretched a...
Wikipedia - Viscoelasticity - Summary
In materials science and engineering, one is often interested in understanding the forces or stresses involved in the deformation of a material. For instance, if the material were a simple spring, the answer would be given by Hooke's law, which says that the force experienced by a spring is proportional to the distance...
Wikipedia - Viscous forces - Dynamic viscosity
These are called viscous stresses. For instance, in a fluid such as water the stresses which arise from shearing the fluid do not depend on the distance the fluid has been sheared; rather, they depend on how quickly the shearing occurs. Viscosity is the material property which relates the viscous stresses in a material...
Wikipedia - Viscous forces - Dynamic viscosity
Although it applies to general flows, it is easy to visualize and define in a simple shearing flow, such as a planar Couette flow. In the Couette flow, a fluid is trapped between two infinitely large plates, one fixed and one in parallel motion at constant speed u {\displaystyle u} (see illustration to the right). If t...
Wikipedia - Viscous forces - Dynamic viscosity
Each layer of fluid moves faster than the one just below it, and friction between them gives rise to a force resisting their relative motion. In particular, the fluid applies on the top plate a force in the direction opposite to its motion, and an equal but opposite force on the bottom plate. An external force is there...
Wikipedia - Viscous forces - Dynamic viscosity
In many fluids, the flow velocity is observed to vary linearly from zero at the bottom to u {\displaystyle u} at the top. Moreover, the magnitude of the force, F {\displaystyle F} , acting on the top plate is found to be proportional to the speed u {\displaystyle u} and the area A {\displaystyle A} of each plate, and i...
Wikipedia - Viscous forces - Dynamic viscosity
The proportionality factor is the dynamic viscosity of the fluid, often simply referred to as the viscosity. It is denoted by the Greek letter mu (μ). The dynamic viscosity has the dimensions ( m a s s / l e n g t h ) / t i m e {\displaystyle \mathrm {(mass/length)/time} } , therefore resulting in the SI units and the ...
Wikipedia - Viscous forces - Dynamic viscosity
If the velocity does not vary linearly with y {\displaystyle y} , then the appropriate generalization is: τ = μ ∂ u ∂ y , {\displaystyle \tau =\mu {\frac {\partial u}{\partial y}},} where τ = F / A {\displaystyle \tau =F/A} , and ∂ u / ∂ y {\displaystyle \partial u/\partial y} is the local shear velocity. This expressi...
Wikipedia - Viscous forces - Dynamic viscosity
In shearing flows with planar symmetry, it is what defines μ {\displaystyle \mu } . It is a special case of the general definition of viscosity (see below), which can be expressed in coordinate-free form. Use of the Greek letter mu ( μ {\displaystyle \mu } ) for the dynamic viscosity (sometimes also called the absolute...
Wikipedia - Viscous forces - Dynamic viscosity
However, the Greek letter eta ( η {\displaystyle \eta } ) is also used by chemists, physicists, and the IUPAC. The viscosity μ {\displaystyle \mu } is sometimes also called the shear viscosity. However, at least one author discourages the use of this terminology, noting that μ {\displaystyle \mu } can appear in non-she...
Wikipedia - Viscous forces - Dynamic viscosity
In materials science and engineering, the yield point is the point on a stress-strain curve that indicates the limit of elastic behavior and the beginning of plastic behavior. Below the yield point, a material will deform elastically and will return to its original shape when the applied stress is removed. Once the yie...
Wikipedia - Yield (engineering) - Summary
The yield strength is often used to determine the maximum allowable load in a mechanical component, since it represents the upper limit to forces that can be applied without producing permanent deformation. In some materials, such as aluminium, there is a gradual onset of non-linear behavior, and no precise yield point...
Wikipedia - Yield (engineering) - Summary
Yielding is a gradual failure mode which is normally not catastrophic, unlike ultimate failure. In solid mechanics, the yield point can be specified in terms of the three-dimensional principal stresses ( σ 1 , σ 2 , σ 3 {\displaystyle \sigma _{1},\sigma _{2},\sigma _{3}} ) with a yield surface or a yield criterion. A v...
Wikipedia - Yield (engineering) - Summary
In materials science and materials engineering, uranium metallurgy is the study of the physical and chemical behavior of uranium and its alloys.Commercial-grade uranium can be produced through the reduction of uranium halides with alkali or alkaline earth metals. Uranium metal can also be made through electrolysis of K...
Wikipedia - Uranium metallurgy - Summary
The uranium isotope 235U is used as the fuel for nuclear reactors and nuclear weapons. It is the only isotope existing in nature to any appreciable extent that is fissile, that is, fissionable by thermal neutrons. The isotope 238U is also important because it absorbs neutrons to produce a radioactive isotope that subse...
Wikipedia - Uranium metallurgy - Summary
In materials science and mathematics, functionally graded elements are elements used in finite element analysis. They can be used to describe a functionally graded material.
Wikipedia - Functionally graded element - Summary
In materials science and metallurgy, toughness is the ability of a material to absorb energy and plastically deform without fracturing. Toughness is the strength with which the material opposes rupture. One definition of material toughness is the amount of energy per unit volume that a material can absorb before ruptur...
Wikipedia - Toughness - Summary
In materials science and molecular biology, thermostability is the ability of a substance to resist irreversible change in its chemical or physical structure, often by resisting decomposition or polymerization, at a high relative temperature. Thermostable materials may be used industrially as fire retardants. A thermos...
Wikipedia - Thermostability - Summary
In materials science and soil mechanics, a slip line field or slip line field theory is a technique often used to analyze the stresses and forces involved in the major deformation of metals or soils. In essence, in some problems including plane strain and plane stress elastic-plastic problems, elastic part of the mater...
Wikipedia - Slip line field - Summary
In materials science and solid mechanics, Poisson's ratio ν {\displaystyle \nu } (nu) is a measure of the Poisson effect, the deformation (expansion or contraction) of a material in directions perpendicular to the specific direction of loading. The value of Poisson's ratio is the negative of the ratio of transverse str...
Wikipedia - Poisson's Ratio - Summary
For soft materials, such as rubber, where the bulk modulus is much higher than the shear modulus, Poisson's ratio is near 0.5. For open-cell polymer foams, Poisson's ratio is near zero, since the cells tend to collapse in compression. Many typical solids have Poisson's ratios in the range of 0.2–0.3. The ratio is named...
Wikipedia - Poisson's Ratio - Summary
In materials science and solid mechanics, biaxial tensile testing is a versatile technique to address the mechanical characterization of planar materials. It is a generalized form of tensile testing in which the material sample is simultaneously stressed along two perpendicular axes. Typical materials tested in biaxial...
Wikipedia - Biaxial tensile testing - Summary
In materials science and solid mechanics, residual stresses are stresses that remain in a solid material after the original cause of the stresses has been removed. Residual stress may be desirable or undesirable. For example, laser peening imparts deep beneficial compressive residual stresses into metal components such...
Wikipedia - Residual stress - Summary
Residual stresses can result from a variety of mechanisms including inelastic (plastic) deformations, temperature gradients (during thermal cycle) or structural changes (phase transformation). Heat from welding may cause localized expansion, which is taken up during welding by either the molten metal or the placement o...
Wikipedia - Residual stress - Summary
In materials science parlance, dislocations are defined as line defects in a material's crystal structure. The bonds surrounding the dislocation are already elastically strained by the defect compared to the bonds between the constituents of the regular crystal lattice. Therefore, these bonds break at relatively lower ...
Wikipedia - Work hardened - Dislocations and lattice strain fields
For example, there are compressively strained bonds directly next to an edge dislocation and tensilely strained bonds beyond the end of an edge dislocation. These form compressive strain fields and tensile strain fields, respectively. Strain fields are analogous to electric fields in certain ways.
Wikipedia - Work hardened - Dislocations and lattice strain fields
Specifically, the strain fields of dislocations obey similar laws of attraction and repulsion; in order to reduce overall strain, compressive strains are attracted to tensile strains, and vice versa. The visible (macroscopic) results of plastic deformation are the result of microscopic dislocation motion. For example, ...
Wikipedia - Work hardened - Dislocations and lattice strain fields
In materials science the flow stress, typically denoted as Yf (or σ f {\displaystyle \sigma _{\text{f}}} ), is defined as the instantaneous value of stress required to continue plastically deforming a material - to keep it flowing. It is most commonly, though not exclusively, used in reference to metals. On a stress-st...
Wikipedia - Flow stress - Summary
In continuum mechanics, the flow stress for a given material will vary with changes in temperature, T {\displaystyle T} , strain, ε {\displaystyle \varepsilon } , and strain-rate, ε ˙ {\displaystyle {\dot {\varepsilon }}} ; therefore it can be written as some function of those properties: Y f = f ( ε , ε ˙ , T ) {\disp...
Wikipedia - Flow stress - Summary
Generally, raising the temperature of an alloy above 0.5 Tm results in the plastic deformation mechanisms being controlled by strain-rate sensitivity, whereas at room temperature metals are generally strain-dependent. Other models may also include the effects of strain gradients. Independent of test conditions, the flo...
Wikipedia - Flow stress - Summary
Fatigue failure is caused by crack propagation in materials under a varying load, typically a cyclically varying load. The rate of crack propagation is inversely proportional to the flow stress of the material. == References ==
Wikipedia - Flow stress - Summary
In materials science, MXenes are a class of two-dimensional inorganic compounds , that consist of atomically thin layers of transition metal carbides, nitrides, or carbonitrides. MXenes accept a variety of hydrophilic terminations. MXenes were first reported in 2012.
Wikipedia - MXenes - Summary
In materials science, Ostwald's rule or Ostwald's step rule, conceived by Wilhelm Ostwald, describes the formation of polymorphs. The rule states that usually the less stable polymorph crystallizes first. Ostwald's rule is not a universal law but a common tendency observed in nature.This can be explained on the basis o...
Wikipedia - Ostwald's step rule - Summary
Unstable polymorphs more closely resemble the state in solution, and thus are kinetically advantaged. For example, out of hot water, metastable, fibrous crystals of benzamide appear first, only later to spontaneously convert to the more stable rhombic polymorph. Another example is magnesium carbonate, which more readil...
Wikipedia - Ostwald's step rule - Summary
A dramatic example is phosphorus, which upon sublimation first forms the less stable white phosphorus, which only slowly polymerizes to the red allotrope. This is notably the case for the anatase polymorph of titanium dioxide, which having a lower surface energy is commonly the first phase to form by crystallisation fr...
Wikipedia - Ostwald's step rule - Summary
In materials science, Schmid's law (also Schmid factor) describes the slip plane and the slip direction of a stressed material, which can resolve the most shear stress. Schmid's Law states that the critically resolved shear stress (τ) is equal to the stress applied to the material (σ) multiplied by the cosine of the an...
Wikipedia - Schmid's law - Summary
In materials science, a Bingham plastic is a viscoplastic material that behaves as a rigid body at low stresses but flows as a viscous fluid at high stress. It is named after Eugene C. Bingham who proposed its mathematical form.It is used as a common mathematical model of mud flow in drilling engineering, and in the ha...
Wikipedia - Bingham fluid - Summary
In materials science, a Frank–Read source is a mechanism explaining the generation of multiple dislocations in specific well-spaced slip planes in crystals when they are deformed. When a crystal is deformed, in order for slip to occur, dislocations must be generated in the material. This implies that, during deformatio...
Wikipedia - Frank-Read source - Summary
Cold working of metal increases the number of dislocations by the Frank–Read mechanism. Higher dislocation density increases yield strength and causes work hardening of metals. The mechanism of dislocation generation was proposed by and named after British physicist Charles Frank and Thornton Read.
Wikipedia - Frank-Read source - Summary
In materials science, a Lomer–Cottrell junction is a particular configuration of dislocations. When two perfect dislocations encounter along a slip plane, each perfect dislocation can split into two Shockley partial dislocations: a leading dislocation and a trailing dislocation. When the two leading Shockley partials c...
Wikipedia - Lomer–Cottrell junction - Summary
It is sessile and immobile in the slip plane, acting as a barrier against other dislocations in the plane. The trailing dislocations pile up behind the Lomer–Cottrell dislocation, and an ever greater force is required to push additional dislocations into the pile-up. ex. FCC lattice along {111} slip planes |leading| |t...
Wikipedia - Lomer–Cottrell junction - Summary
In materials science, a composite laminate is an assembly of layers of fibrous composite materials which can be joined to provide required engineering properties, including in-plane stiffness, bending stiffness, strength, and coefficient of thermal expansion. The individual layers consist of high-modulus, high-strength...
Wikipedia - Composite laminate - Summary
Layers of different materials may be used, resulting in a hybrid laminate. The individual layers generally are orthotropic (that is, with principal properties in orthogonal directions) or transversely isotropic (with isotropic properties in the transverse plane) with the laminate then exhibiting anisotropic (with varia...
Wikipedia - Composite laminate - Summary
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...
Wikipedia - Dislocation - Summary
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...
Wikipedia - Dislocation - Summary
The number and arrangement of dislocations influences many of the properties of materials. The two primary types of dislocations are sessile dislocations which are immobile and glissile dislocations which are mobile. Examples of sessile dislocations are the stair-rod dislocation and the Lomer–Cottrell junction.
Wikipedia - Dislocation - Summary
The two main types of mobile dislocations are edge and screw dislocations. Edge dislocations can be visualized as being caused by the termination of a plane of atoms in the middle of a crystal. In such a case, the surrounding planes are not straight, but instead bend around the edge of the terminating plane so that the...
Wikipedia - Dislocation - Summary
This phenomenon is analogous to half of a piece of paper inserted into a stack of paper, where the defect in the stack is noticeable only at the edge of the half sheet. The theory describing the elastic fields of the defects was originally developed by Vito Volterra in 1907. In 1934, Egon Orowan, Michael Polanyi and G....
Wikipedia - Dislocation - Summary
In materials science, a general rule of mixtures is a weighted mean used to predict various properties of a composite material . It provides a theoretical upper- and lower-bound on properties such as the elastic modulus, ultimate tensile strength, thermal conductivity, and electrical conductivity. In general there are ...
Wikipedia - Rule of mixtures - Summary
The real upper-bound Young's modulus is larger than E c {\displaystyle E_{c}} given by this formula. Even if both constituents are isotropic, the real upper bound is E c {\displaystyle E_{c}} plus a term in the order of square of the difference of the Poisson's ratios of the two constituents.The inverse rule of mixture...
Wikipedia - Rule of mixtures - Summary
In materials science, a grain boundary is the interface between two grains, or crystallites, in a polycrystalline material. Grain boundaries are two-dimensional defects in the crystal structure, and tend to decrease the electrical and thermal conductivity of the material. Most grain boundaries are preferred sites for t...
Wikipedia - Grain boundary - Summary
In materials science, a matrix is a constituent of a composite material.
Wikipedia - Matrix (composite) - Summary
In materials science, a metal foam is a material or structure consisting of a solid metal (frequently aluminium) with gas-filled pores comprising a large portion of the volume. The pores can be sealed (closed-cell foam) or interconnected (open-cell foam). The defining characteristic of metal foams is a high porosity: t...
Wikipedia - Sponge metal - Summary
Metal foams typically retain some physical properties of their base material. Foam made from non-flammable metal remains non-flammable and can generally be recycled as the base material. Its coefficient of thermal expansion is similar while thermal conductivity is likely reduced.
Wikipedia - Sponge metal - Summary
In materials science, a metal matrix composite (MMC) is a composite material with fibers or particles dispersed in a metallic matrix, such as copper, aluminum, or steel. The secondary phase is typically a ceramic (such as alumina or silicon carbide) or another metal (such as steel). They are typically classified accord...
Wikipedia - Metal matrix composite - Summary