query: What metal has the highest melting point?

title: Melting point

text: of ice at 1 atmosphere of pressure is very close to ; this is also known as the ice point. In the presence of nucleating substances, the freezing point of water is not always the same as the melting point. In the absence of nucleators water can exist as a supercooled liquid down to −48.3 °C (−55 °F, 224.8 K) before freezing. The chemical element with the highest melting point is tungsten, at ; this property makes tungsten excellent for use as filaments in light bulbs. The often-cited carbon does not melt at ambient pressure but sublimes at about ;

title: Glass-to-metal seal

text: formation of lithium tungstate. Due to its low thermal expansion coefficient, matched to glass, tungsten is frequently used for glass-metal bonds. Tungsten forms satisfying bonds with glasses with similar thermal expansion coefficient such as high-borosilicate glass. The surface of both the metal and glass should be smooth, without scratches. Tungsten has the lowest expansion coefficient of metals and the highest melting point. 304 Stainless steel forms bonds with glass via an intermediate layer of chromium(III) oxide and iron(III) oxide. Further reactions of chromium, forming chromium silicide dendrites, are possible. The thermal expansion coefficient of steel is however fairly different from

title: Melting point

text: of the individual crystals at a certain temperature can be observed. In large/small devices, the sample is placed in a heating block, and optical detection is automated. The measurement can also be made continuously with an operating process. For instance, oil refineries measure the freeze point of diesel fuel online, meaning that the sample is taken from the process and measured automatically. This allows for more frequent measurements as the sample does not have to be manually collected and taken to a remote laboratory. For refractory materials (e.g. platinum, tungsten, tantalum, some carbides and nitrides, etc.) the extremely high melting

title: Incandescent light bulb

text: direction. Compared to general-service bulbs, for the same power, these bulbs produce far more light, and (more importantly) light at a higher color temperature, at the expense of greatly reduced life (which may be as short as two hours for a type P1 lamp). The upper temperature limit for the filament is the melting point of the metal. Tungsten is the metal with the highest melting point, . A 50-hour-life projection bulb, for instance, is designed to operate only below that melting point. Such a lamp may achieve up to 22 lumens per watt, compared with 17.5 for a 750-hour

title: Melting-point depression

text: in Figure 1, and the shape of the curve is in general agreement with those obtained through experiment. Equation 2 gives the general relation between the melting point of a metal nanoparticle and its diameter. However, recent work indicates the melting point of semiconductor and covalently bonded nanoparticles may have a different dependence on particle size. The covalent character of the bonds changes the melting physics of these materials. Researchers have demonstrated that Equation 3 more accurately models melting point depression in covalently bonded materials. formula_3 Where: T=Bulk Melting temperature Equation 3 indicates that melting point depression is less pronounced

title: Melting-point depression

text: during experiment. Melting point depression was predicted in 1909 by Pawlow. Takagi first observed melting point depression of several types of metal nanoparticles in 1954. A variable intensity electron beam from a transmission electron microscope melted metal nanoparticles in early experiments. Diffraction patterns changed from characteristic crystalline patterns to liquid patterns as the small particles melted, allowing Takagi to estimate the melting temperature from the electron beam energy. Nanoparticles have a much greater surface to volume ratio than bulk materials. The increased surface to volume ratio means surface atoms have a much greater effect on chemical and physical properties of

title: Pressure melting point

text: flux from below and atmospheric warming or cooling from above. As the pressure increases with depth in a glacier from the weight of the ice above, the pressure melting point of ice decreases within bounds, as shown in the diagram. The level where ice can start melting is where the pressure melting point equals the actual temperature. In static equilibrium conditions, this would be the highest level where water can exist in a glacier. It would also be the level of the base of an ice shelf, or the ice-water interface of a subglacial lake. Pressure melting point The pressure

title: Melting point

text: with high melting point". Carnelley based his rule on examination of 15,000 chemical compounds. For example, for three structural isomers with molecular formula CH the melting point increases in the series isopentane −160 °C (113 K) n-pentane −129.8 °C (143 K) and neopentane −16.4 °C (256.8 K). Likewise in xylenes and also dichlorobenzenes the melting point increases in the order meta, ortho and then para. Pyridine has a lower symmetry than benzene hence its lower melting point but the melting point again increases with diazine and triazines. Many cage-like compounds like adamantane and cubane with high symmetry have relatively high

title: Melting point

text: graphically to the right, but also of Si, Ge, Ga, Bi. With extremely large changes in pressure, substantial changes to the melting point are observed. For example, the melting point of silicon at ambient pressure (0.1 MPa) is 1415 °C, but at pressures in excess of 10 GPa it decreases to 1000 °C. Melting points are often used to characterize organic and inorganic compounds and to ascertain their purity. The melting point of a pure substance is always higher and has a smaller range than the melting point of an impure substance or, more generally, of mixtures. The higher the

title: Melting-point depression

text: and thermal properties. This article focuses on nanoparticles because researchers have compiled a large amount of size-dependent melting data for near spherical nanoparticles. Nanoparticles are easiest to study due their ease of fabrication and simplified conditions for theoretical modeling. The melting temperature of a nanoparticle decreases sharply as the particle reaches critical diameter, usually < 50 nm for common engineering metals. Figure 1 shows the shape of a typical melting curve for a metal nanoparticle as a function of its diameter. Melting point depression is a very important issue for applications involving nanoparticles, as it decreases the functional range of

title: Melting point

text: being measured. The containment of the high melting material in the liquid state may introduce experimental difficulties. Melting temperatures of some refractory metals have thus been measured by observing the radiation from a black body cavity in solid metal specimens that were much longer than they were wide. To form such a cavity, a hole is drilled perpendicular to the long axis at the center of a rod of the material. These rods are then heated by passing a very large current through them, and the radiation emitted from the hole is observed with an optical pyrometer. The point of

title: Melting point

text: a liquid phase only exists above pressures of and estimated (see ). Tantalum hafnium carbide (TaHfC) is a refractory compound with a very high melting point of 4215 K (3942 °C, 7128 °F). At the other end of the scale, helium does not freeze at all at normal pressure even at temperatures close to absolute zero; a pressure of more than twenty times normal atmospheric pressure is necessary. Many laboratory techniques exist for the determination of melting points. A Kofler bench is a metal strip with a temperature gradient (range from room temperature to 300 °C). Any substance can be

title: Melting point

text: Open melting point data are also available from "Nature Precedings". High quality data mined from patents and also models developed with these data were published by Tetko "et al". Melting point The melting point (or, rarely, liquefaction point) of a substance is the temperature at which it changes state from solid to liquid. At the melting point the solid and liquid phase exist in equilibrium. The melting point of a substance depends on pressure and is usually specified at a standard pressure such as 1 atmosphere or 100 kPa. When considered as the temperature of the reverse change from liquid

title: Melting point

text: Melting point The melting point (or, rarely, liquefaction point) of a substance is the temperature at which it changes state from solid to liquid. At the melting point the solid and liquid phase exist in equilibrium. The melting point of a substance depends on pressure and is usually specified at a standard pressure such as 1 atmosphere or 100 kPa. When considered as the temperature of the reverse change from liquid to solid, it is referred to as the freezing point or crystallization point. Because of the ability of some substances to supercool, the freezing point is not considered as

title: Melting point

text: "ΔH" are respectively the temperature at the melting point, change of entropy of melting and the change of enthalpy of melting. The melting point is sensitive to extremely large changes in pressure, but generally this sensitivity is orders of magnitude less than that for the boiling point, because the solid-liquid transition represents only a small change in volume. If, as observed in most cases, a substance is more dense in the solid than in the liquid state, the melting point will increase with increases in pressure. Otherwise the reverse behavior occurs. Notably, this is the case of water, as illustrated

title: Melting point

text: a characteristic property of a substance. When the "characteristic freezing point" of a substance is determined, in fact the actual methodology is almost always "the principle of observing the disappearance rather than the formation of ice", that is, the melting point. For most substances, melting and freezing points are approximately equal. For example, the melting point "and" freezing point of mercury is 234.32 kelvins (−38.83 °C or −37.89 °F). However, certain substances possess differing solid-liquid transition temperatures. For example, agar melts at 85 °C (185 °F) and solidifies from ; such direction dependence is known as hysteresis. The melting point

title: Melting-point apparatus

text: Melting-point apparatus A melting-point apparatus is a scientific instrument used to determine the melting point of a substance. Some types of melting-point apparatuses include the Thiele tube, Fisher-Johns apparatus, Gallenkamp (Electronic) melting-point apparatus and automatic melting-point apparatus. While the outward designs of apparatuses can vary greatly, most apparatuses use a sample loaded into a sealed capillary ("melting-point capillary"), which is then placed in the apparatus. The sample is then heated, either by a heating block or an oil bath, and as the temperature increases, the sample is observed to determine when the phase change from solid to liquid occurs. The

title: Melting point

text: point (typically considered to be above, say, 1800 °C) may be determined by heating the material in a black body furnace and measuring the black-body temperature with an optical pyrometer. For the highest melting materials, this may require extrapolation by several hundred degrees. The spectral radiance from an incandescent body is known to be a function of its temperature. An optical pyrometer matches the radiance of a body under study to the radiance of a source that has been previously calibrated as a function of temperature. In this way, the measurement of the absolute magnitude of the intensity of radiation

title: Pressure melting point

text: Pressure melting point The pressure melting point is the temperature at which ice melts at a given pressure. The pressure melting point is nearly a constant 0 °C at pressures above the triple point at 611.7 Pa, where water can exist in only the solid or liquid phases, through atmospheric pressure (100 kPa) until about 10 MPa. With increasing pressure above 10 MPa, the pressure melting point decreases to a minimum of −21.9 °C at 209.9 MPa. Thereafter, the pressure melting point rises rapidly with pressure, passing back through 0 °C at 632.4 MPa. Glaciers are subject to geothermal heat

title: Melting point

text: melting points. A high melting point results from a high heat of fusion, a low entropy of fusion, or a combination of both. In highly symmetrical molecules the crystal phase is densely packed with many efficient intermolecular interactions resulting in a higher enthalpy change on melting. An attempt to predict the bulk melting point of crystalline materials was first made in 1910 by Frederick Lindemann. The idea behind the theory was the observation that the average amplitude of thermal vibrations increases with increasing temperature. Melting initiates when the amplitude of vibration becomes large enough for adjacent atoms to partly occupy

title: Melting point

text: quantity of other components, the lower the melting point and the broader will be the melting point range, often referred to as the "pasty range". The temperature at which melting begins for a mixture is known as the "solidus" while the temperature where melting is complete is called the "liquidus". Eutectics are special types of mixtures that behave like single phases. They melt sharply at a constant temperature to form a liquid of the same composition. Alternatively, on cooling a liquid with the eutectic composition will solidify as uniformly dispersed, small (fine-grained) mixed crystals with the same composition. In contrast

title: Melting-point depression

text: Melting-point depression The melting temperature of a bulk material is not dependent on its size. However, as the dimensions of a material decrease towards the atomic scale, the melting temperature scales with the material dimensions. The decrease in melting temperature can be on the order of tens to hundreds of degrees for metals with nanometer dimensions. Melting-point depression is most evident in nanowires, nanotubes and nanoparticles, which all melt at lower temperatures than bulk amounts of the same material. Changes in melting point occur because nanoscale materials have a much larger surface-to-volume ratio than bulk materials, drastically altering their thermodynamic

title: Melting point

text: placed on a section of the strip, revealing its thermal behaviour at the temperature at that point. Differential scanning calorimetry gives information on melting point together with its enthalpy of fusion. A basic melting point apparatus for the analysis of crystalline solids consists of an oil bath with a transparent window (most basic design: a Thiele tube) and a simple magnifier. The several grains of a solid are placed in a thin glass tube and partially immersed in the oil bath. The oil bath is heated (and stirred) and with the aid of the magnifier (and external light source) melting

title: Slip melting point

text: for fats and waxes, because they tend to be mixtures of compounds with a range of molecular masses, without well-defined melting points. Slip melting point The Slip melting point (SMP) or "slip point" is one conventional definition of the melting point of a waxy solid. It is determined by casting a 10 mm column of the solid in a glass tube with an internal diameter of about 1 mm and a length of about 80 mm, and then immersing it in a temperature-controlled water bath. The slip point is the temperature at which the column of the solid begins to

title: Melting point

text: as Several other expressions for the estimated melting temperature can be obtained depending on the estimate of the average thermal energy. Another commonly used expression for the Lindemann criterion is From the expression for the Debye frequency for "ν", we have where "θ" is the Debye temperature and "h" is the Planck constant. Values of "c" range from 0.15–0.3 for most materials. In February 2011, Alfa Aesar released over 10,000 melting points of compounds from their catalog as open data. This dataset has been used to create a random forest model for melting point prediction which is now freely available.

title: Melting-point depression

text: simulations theorize that the supporting substrate affects the extent of melting-point depression of a nanoparticle. These models account for energetic interactions between the substrate materials. A free nanoparticle, as many theoretical models assume, has a different melting temperature (usually lower) than a supported particle due to the absence cohesive energy between the nanoparticle and substrate. However, measurement of the properties of a freestanding nanoparticle remains impossible, so the extent of the interactions cannot be verified through experiment. Ultimately, substrates currently support nanoparticles for all nanoparticle applications, so substrate/nanoparticle interactions are always present and must impact melting point depression. Within the

title: Melting-point depression

text: which affects the cohesive energy and thermal properties of a nanostructure. Equation 7 gives a general shape corrected formula for the theoretical melting point of a nanoparticle based on its size and shape. formula_7 Where: c=materials constant The shape parameter is 1 for sphere and 3/2 for a very long wire, indicating that melting-point depression is suppressed in nanowires compared to nanoparticles. Past experimental data show that nanoscale tin platelets melt within a narrow range of 10 C of the bulk melting temperature. The melting point depression of these platelets was suppressed compared to spherical tin nanoparticles. Several nanoparticle melting

title: Melting point

text: to be supplied for the melting to take place: this is called the heat of fusion, and is an example of latent heat. From a thermodynamics point of view, at the melting point the change in Gibbs free energy (ΔG) of the material is zero, but the enthalpy ("H") and the entropy ("S") of the material are increasing (ΔH, ΔS > 0). Melting phenomenon happens when the Gibbs free energy of the liquid becomes lower than the solid for that material. At various pressures this happens at a specific temperature. It can also be shown that: Here "T", "ΔS" and

title: Melting point

text: melting is indicated by the darkening of the hole when the liquid phase appears, destroying the black body conditions. Today, containerless laser heating techniques, combined with fast pyrometers and spectro-pyrometers, are employed to allow for precise control of the time for which the sample is kept at extreme temperatures. Such experiments of sub-second duration address several of the challenges associated with more traditional melting point measurements made at very high temperatures, such as sample vaporization and reaction with the container. For a solid to melt, heat is required to raise its temperature to the melting point. However, further heat needs

title: Slip melting point

text: Slip melting point The Slip melting point (SMP) or "slip point" is one conventional definition of the melting point of a waxy solid. It is determined by casting a 10 mm column of the solid in a glass tube with an internal diameter of about 1 mm and a length of about 80 mm, and then immersing it in a temperature-controlled water bath. The slip point is the temperature at which the column of the solid begins to rise in the tube due to buoyancy, and because the outside surface of the solid is molten. This is a popular method

title: Melting-point depression

text: phonons), Photon emission and absorption, electronic colevel shift and work function modulation, magnetism at various temperatures, and dielectrics due to electron polarization etc. Reproduction of experimental observations in the above-mentioned size dependency has been realized. Quantitative information such as the energy level of an isolated atom and the vibration frequency of individual dimer has been obtained by matching the BOLS predictions to the measured size dependency. Nanoparticle shape impacts the melting point of a nanoparticle. Facets, edges and deviations from a perfect sphere all change the magnitude of melting point depression. These shape changes affect the surface to volume ratio,

title: Melting-point depression

text: size–pressure approximation, which considers the stress induced by the surface tension and the curvature of the particle, it was shown that the size of the particle affects the composition and temperature of a eutectic point (Fe-C) the solubility of C in Fe and Fe:Mo nanoclusters. Reduced solubility can affect the catalytic properties of nanoparticles. In fact it has been shown that size-induced instability of Fe-C mixtures represents the thermodynamic limit for the thinnest nanotube that can be grown from Fe nanocatalysts. Melting-point depression The melting temperature of a bulk material is not dependent on its size. However, as the dimensions

title: Melting-point depression

text: to its cohesive energy, a (T=Ca). Since atoms near the surface have fewer bonds and reduced cohesive energy, they require less energy to free from the solid phase. Melting point depression of high surface to volume ratio materials results from this effect. For the same reason, surfaces of bulk materials can melt at lower temperatures than the bulk material. The theoretical size-dependent melting point of a material can be calculated through classical thermodynamic analysis. The result is the Gibbs–Thomson equation shown in Equation 2. formula_2 Where: T = Bulk Melting temperature A normalized Gibbs–Thomson Equation for gold nanoparticles is plotted

title: Melting-point apparatus

text: range to be recorded. A Thiele tube is a glass instrument that is filled with oil that is heated by using an open flame. The sample is placed in the opening in a capillary tube alongside a mercury thermometer and allowed to be heated by the oil as it circulates through the Thiele tube. By using different oils, different temperature ranges can be reached and used to determine melting points. The Thiele tube may also be used to determine boiling points, by using a liquid sample instead of a solid sample. Melting-point apparatus A melting-point apparatus is a scientific instrument

title: Melting point

text: to crystalline solids, glasses do not possess a melting point; on heating they undergo a smooth glass transition into a viscous liquid. Upon further heating, they gradually soften, which can be characterized by certain softening points. The freezing point of a solvent is depressed when another compound is added, meaning that a solution has a lower freezing point than a pure solvent. This phenomenon is used in technical applications to avoid freezing, for instance by adding salt or ethylene glycol to water. In organic chemistry, Carnelley's rule, established in 1882 by Thomas Carnelley, states that "high molecular symmetry is associated

title: Melting point

text: the same space. The Lindemann criterion states that melting is expected when the vibration root mean square amplitude exceeds a threshold value. Assuming that all atoms in a crystal vibrate with the same frequency "ν", the average thermal energy can be estimated using the equipartition theorem as where "m" is the atomic mass, "ν" is the frequency, "u" is the average vibration amplitude, "k" is the Boltzmann constant, and "T" is the absolute temperature. If the threshold value of "u" is "ca" where "c" is the Lindemann constant and "a" is the atomic spacing, then the melting point is estimated

title: Filler metal

text: point than the base metal, so that the joint may be made by bringing the whole assembly up to temperature without everything melting as one. Complex joints, typically for jewellery or live steam boilermaking may be made in stages, with filler metals of progressively lower melting points used in turn. Early joints are thus not destroyed by heating to the later temperatures. Welding processes work around the melting point of the base metal and require the base metal itself to begin melting. They usually require more precise distribution of heat from a small torch, as melting the entire workpiece is

title: Pot metal

text: Pot metal Pot metal (or monkey metal) is an alloy of low-melting point metals that manufacturers use to make fast, inexpensive castings. The term "pot metal" came about due to the practice at automobile factories in the early 20th century of gathering up non-ferrous metal scraps from the manufacturing processes and melting them in one pot to form into cast products. A small amount of iron usually made it into the castings, but too much iron raised the melting point, so it was minimized. There is no metallurgical standard for pot metal. Common metals in pot metal include zinc, lead,

title: Melting-point apparatus

text: operator of the apparatus records the temperature range starting with the initial phase-change temperature and ending with the completed phase-change temperature. The temperature range that is determined can then be averaged to gain the melting point of the sample being examined. Apparatuses usually have a control panel that allows the starting and final temperatures, as well as the temperature gradient (in units per minute), to be programmed. Some machines have several channels, which permit more than one sample to be tested at a time. The control panel might have buttons that allow the start and end of the melting point

title: Melting-point depression

text: the interfacial energies between the solid and liquid phases, volumes and surface areas of each phase, and size of the nanoparticle. The model calculations show that the liquid phase forms at lower temperatures for smaller nanoparticles. Once the liquid phase forms, the free energy conditions quickly change and favor melting. Equation 6 gives the melting conditions for a spherical nanoparticle according to the LNG model. formula_6 The bond-order-length-strength (BOLS) model employs an atomistic approach to explain melting point depression. The model focuses on the cohesive energy of individual atoms rather than a classical thermodynamic approach. The BOLS model calculates the

title: Melting-point depression

text: predicts a sharp, unmoving interface between the solid and liquid phases at a given temperature. The exact thickness of the liquid layer at a given temperature is the equilibrium point between the competing Landau potentials. Equation 5 gives the condition at which an entire nanoparticle melts according to the LSN model. formula_5 Where: d=atomic diameter The liquid nucleation and growth model (LNG) treats nanoparticle melting as a surface initiated process. The surface melts initially, and the liquid-solid interface quickly advances through the entire nanoparticle. The LNG defines melting conditions through the Gibbs-Duhem relations, yielding a melting temperature function dependent on

title: Melting-point depression

text: it possible to test and characterize samples with a wider distribution of particle sizes. The TEM limits the pressure range at which melting point depression can be tested. More recently, researchers developed nanocalorimeters that directly measure the enthalpy and melting temperature of nanoparticles. Nanocalorimeters provide the same data as bulk calorimeters, however additional calculations must account for the presence of the substrate supporting the particles. A narrow size distribution of nanoparticles is required since the procedure does not allow users to view the sample during the melting process. There is no way to characterize the exact size of melted particles

title: Flux melting

text: the mantle, where these volatiles are released by metamorphic dewatering into the overlying mantle wedge. The partial melting triggered by the incorporation of volatiles produces mafic magma which rises and differentiates forming the igneous and volcanic rocks of the overlying volcanic arc. Flux melting In igneous petrology, flux melting occurs when water and other volatile components are added to hot solid rock. In engineering and metallurgy, flux is a substance, such as salt, that produces a low melting point mixture with a metal oxide. In the same way, the addition of water and other volatile compounds to rocks composed of

title: Flux melting

text: Flux melting In igneous petrology, flux melting occurs when water and other volatile components are added to hot solid rock. In engineering and metallurgy, flux is a substance, such as salt, that produces a low melting point mixture with a metal oxide. In the same way, the addition of water and other volatile compounds to rocks composed of silicate minerals lowers the melting temperature of those rocks. In subduction zones, the ultramafic rock of the upper mantle is melted by the addition of volatiles from the down-going plate. The subducting slab of oceanic crust carries water and other volatiles into

title: Metal-induced embrittlement

text: Metal-induced embrittlement Metal-induced embrittlement (MIE) is the embrittlement caused by diffusion of metal, either solid or liquid, into the base material. Metal induced embrittlement occurs when metals are in contact with low-melting point metals while under tensile stress. The embrittler can be either solid (SMIE) or liquid (Liquid metal embrittlement). Under sufficient tensile stress, MIE failure occurs instantaneously at temperatures just above melting point. For temperatures below the melting temperature of the embrittler, solid-state diffusion is the main transport mechanism. This occurs in the following ways: The main mechanism of transport for SMIE is surface self-diffusion of the embrittler over

title: Metal-induced embrittlement

text: be introduced during fabrication, coatings, testing or during service of the material components. Susceptibility for SMIE increases with the following material characteristics: Metal-induced embrittlement Metal-induced embrittlement (MIE) is the embrittlement caused by diffusion of metal, either solid or liquid, into the base material. Metal induced embrittlement occurs when metals are in contact with low-melting point metals while under tensile stress. The embrittler can be either solid (SMIE) or liquid (Liquid metal embrittlement). Under sufficient tensile stress, MIE failure occurs instantaneously at temperatures just above melting point. For temperatures below the melting temperature of the embrittler, solid-state diffusion is the main

title: Melting-point depression

text: the solid phase. Nanoparticles are currently used or proposed for prominent roles in catalyst, sensor, medicinal, optical, magnetic, thermal, electronic, and alternative energy applications. Nanoparticles must be in the solid state to function at elevated temperatures in several of these applications. Two techniques allow measurement of the melting point of nanoparticle. The electron beam of a transmission electron microscope (TEM) can be used to melt nanoparticles. The melting temperature is estimated from the beam intensity, while changes in the diffraction conditions to indicate phase transition from solid to liquid. This method allows direct viewing of nanoparticles as they melt, making

title: Vacuum induction melting

text: Vacuum induction melting Vacuum induction melting (VIM) utilizes electric currents to melt metal within a vacuum. The first prototype was developed in 1920. One of the only ways to induce a current within a conductor is through electromagnetic induction. Electromagnetic induction induces eddy currents within conductors by changing the magnetic field. Eddy currents create heating effects to melt the metal. Vacuum induction melting has been used in both the aerospace and nuclear industries. The process was invented in Hanau, Germany in 1917. Heraeus Vacuumschmelze and Dr. Wilhelm Rohn applied for a patent on vacuum melting on 12 January 1918 and

title: Liquid metal

text: Liquid metal Liquid metal consists of alloys with very low melting points which form a eutectic that is liquid at room temperature. The standard metal used to be mercury, but gallium-based alloys, which are lower both in their vapor pressure at room temperature and toxicity, are being used as a replacement in various applications. A few elemental metals are liquid at or near room temperature. The most well known is mercury(Hg), which is molten above −38.8 °C (234.3 K, −37.9 °F). Others include caesium(Cs), which has a melting point of 28.5 °C (83.3 °F), rubidium (Rb)(39 °C [102 °F]), francium

title: Wood's metal

text: is a non-toxic alternative. The dust may form flammable mixtures with air. Several other alloys with similar low melting points are listed here. Wood's metal Wood's metal, also known as Lipowitz's alloy or by the commercial names Cerrobend, Bendalloy, Pewtalloy and MCP 158, is a eutectic, fusible alloy with a melting point of approximately . It is a eutectic alloy of 50% bismuth, 26.7% lead, 13.3% tin, and 10% cadmium by weight. The alloy is named for Barnabas Wood. Wood's metal is useful as a low-melting solder, low-temperature casting metal, high-temperature coupling fluid in heat baths, and as a fire-melted

title: The Melting Pot (comics)

text: of the story, filling an entire issue of "Heavy Metal" magazine. The 2007 version is substantially different from the original series, with an expanded, more coherent narrative and new artwork by Eastman, Bisley, and Rob Prior. Key characters and other elements of the Melting Pot story became the basis for the direct-to-video animated film "Heavy Metal 2000" in 2000. The Melting Pot (comics) The Melting Pot is a graphic novel by Kevin Eastman, Simon Bisley and Eric Talbot. Eastman and Talbot collaborated on the story, while Eastman and Bisley worked together on the painted artwork. The series spent several years

title: Melting point

text: medium is then removed and the current through the filament is adjusted to match the filament intensity to that of the black-body. This establishes a second calibration point for the pyrometer. This step is repeated to carry the calibration to higher temperatures. Now, temperatures and their corresponding pyrometer filament currents are known and a curve of temperature versus current can be drawn. This curve can then be extrapolated to very high temperatures. In determining melting points of a refractory substance by this method, it is necessary to either have black body conditions or to know the emissivity of the material

title: Melting point

text: light intensity of the filament matches that of a black-body at the melting point of gold. This establishes the primary calibration temperature and can be expressed in terms of current through the pyrometer lamp. With the same current setting, the pyrometer is sighted on another black-body at a higher temperature. An absorbing medium of known transmission is inserted between the pyrometer and this black-body. The temperature of the black-body is then adjusted until a match exists between its intensity and that of the pyrometer filament. The true higher temperature of the black-body is then determined from Planck's Law. The absorbing

title: Selective laser melting

text: Selective laser melting Selective laser melting (SLM), also known as direct metal laser sintering (DMLS) or laser powder bed fusion (LPBF), is a rapid prototyping, 3D printing, or additive manufacturing (AM) technique designed to use a high power-density laser to melt and fuse metallic powders together. In many SLM is considered to be a subcategory of selective laser sintering (SLS). The SLM process has the ability to fully melt the metal material into a solid three-dimensional part unlike SLS. Selective laser melting, one of the several 3D printing technologies, started in 1995 at the Fraunhofer Institute ILT in Aachen, Germany,

title: Wood's metal

text: Wood's metal Wood's metal, also known as Lipowitz's alloy or by the commercial names Cerrobend, Bendalloy, Pewtalloy and MCP 158, is a eutectic, fusible alloy with a melting point of approximately . It is a eutectic alloy of 50% bismuth, 26.7% lead, 13.3% tin, and 10% cadmium by weight. The alloy is named for Barnabas Wood. Wood's metal is useful as a low-melting solder, low-temperature casting metal, high-temperature coupling fluid in heat baths, and as a fire-melted valve element in fire sprinkler systems in buildings. Medical gas cylinders in the United Kingdom have a Wood's metal seal which melts in

title: Melting-point depression

text: in covalent nanoparticles due to the quadratic nature of particle size dependence in the melting Equation. The specific melting process for nanoparticles is currently unknown. The scientific community currently accepts several mechanisms as possible models of nanoparticle melting. Each of the corresponding models effectively match experimental data for melting of nanoparticles. Three of the four models detailed below derive the melting temperature in a similar form using different approaches based on classical thermodynamics. The liquid drop model (LDM) assumes that an entire nanoparticle transitions from solid to liquid at a single temperature. This feature distinguishes the model, as the other

title: Congruent melting

text: CDE for the three solid phases. In the phase diagram, we can notice that the top point D of the phase diagram is the congruent melting point of the compound AB because the solid and liquid phases now have the same composition. Evidently, at this temperature, the two-component system has become a one-component system because both solid and liquid phases contains only the compound AB. This happens for inter-metallic compounds. For example, MgSi Congruent melting Congruent melting occurs during melting of a compound when the composition of the liquid that forms is the same as the composition of the solid.

title: Melting

text: sufficient rigidity to mechanically withstand load. Under a standard set of conditions, the melting point of a substance is a characteristic property. The melting point is often equal to the freezing point. However, under carefully created conditions, supercooling or superheating past the melting or freezing point can occur. Water on a very clean glass surface will often supercool several degrees below the freezing point without freezing. Fine emulsions of pure water have been cooled to −38 degrees Celsius without nucleation to form ice. Nucleation occurs due to fluctuations in the properties of the material. If the material is kept still

title: Melting-point depression

text: radius. The parabolic Landau potentials for the liquid and solid phases are calculated at a given temperature, with the lesser Landau a potential assumed to be the equilibrium state at any point in the particle. In the temperature range of surface melting, the results show that the Landau curve of the ordered state is favored near the center of the particle while the Landau curve of the disordered state is smaller near the surface of the particle. The Landau curves intersect at a specific radius from the center of the particle. The distinct intersection of the potentials means the LSN

title: Melting-point depression

text: cohesive energy per bond between atoms, independent of the exact form of the specific interatomic potential. However, the integrated cohesive energy for surface atoms is much lower than bulk atoms due to the reduced coordination number and overall decrease in cohesive energy. Using a core–shell configuration, the melting point depression of nanoparticles is dominated by the outermost two atomic layers yet atoms in the core interior remain their bulk nature. The BOLS model and the core–shell structure have been applied to other size dependency of nanostructures such as the mechanical strength, chemical and thermal stability, lattice dynamics (optical and acoustic

title: Melting

text: Melting Melting, or fusion, is a physical process that results in the phase transition of a substance from a solid to a liquid. This occurs when the internal energy of the solid increases, typically by the application of heat or pressure, which increases the substance's temperature to the melting point. At the melting point, the ordering of ions or molecules in the solid breaks down to a less ordered state, and the solid melts to become a liquid. Substances in the molten state generally have reduced viscosity as the temperature increases. An exception to this principle is the element sulfur,

title: Alkali metal

text: changes state from solid to liquid while the boiling point of a substance (in liquid state) is the point where the vapour pressure of the liquid equals the environmental pressure surrounding the liquid and all the liquid changes state to gas. As a metal is heated to its melting point, the metallic bonds keeping the atoms in place weaken so that the atoms can move around, and the metallic bonds eventually break completely at the metal's boiling point. Therefore, the falling melting and boiling points of the alkali metals indicate that the strength of the metallic bonds of the alkali

title: Melting

text: whose viscosity increases to a point due to polymerization and then decreases with higher temperatures in its molten state. Some organic compounds melt through mesophases, states of partial order between solid and liquid. From a thermodynamics point of view, at the melting point the change in Gibbs free energy "∆G" of the substances is zero, but there are non-zero changes in the enthalpy ("H") and the entropy ("S"), known respectively as the enthalpy of fusion (or latent heat of fusion) and the entropy of fusion. Melting is therefore classified as a first-order phase transition. Melting occurs when the Gibbs free

title: Glass-to-metal seal

text: glass on the metal. If the contact angle is low (good wetting) the surface of the glass is everywhere under compression stress like an enamel coating. Ordinary soda-lime glass does not flow on copper at temperatures below the melting point of the copper and, thus, does not give a low contact angle. The solution is to cover the copper with a solder glass which has a low melting point and does flow on copper and then to press the soft soda-lime glass onto the copper. The solder glass must have a coefficient of thermal expansion which is equal or a

title: Metal-induced embrittlement

text: a layer of embrittler that’s thick enough to be characterized as self-diffusion at the crack tip. In comparison, LMIE dominant mechanism is bulk liquid flow that penetrates at the tips of cracks. Studies have shown that Zn, Pb, Cd, Sn and In can embrittle steel at temperature below each embrittler’s melting point. Similar to liquid metal embrittlement (LME), solid metal-induced embrittlement results in a decrease in fracture strength of a material. In addition, a decrease in tensile ductility over a temperature range is indicative of metal-induced embrittlement. Although SMIE is greatest just below the embrittler’s melting temperature, the range over

title: Desktop Metal

text: plastic printers do.” When the shape is complete, it is placed in a furnace which burns away the polymers and “compacts the metal particles by sintering them together at just below their melting point." At that temperature the metal is fused without melting and losing its shape. The sintering causes predictable shrinking, which the system’s software compensates for by making items slightly larger during the printing step. Beyond the printer and furnace, the Studio System also includes a debinder to remove part of the polymer binder before sintering. The Production System uses a printing method where droplets of a binding

title: Melting

text: amorphous materials. Even below its melting point, quasi-liquid films can be observed on crystalline surfaces. The thickness of the film is temperature dependent. This effect is common for all crystalline materials. Pre-melting shows its effects in e.g. frost heave, the growth of snowflakes and, taking grain boundary interfaces into account, maybe even in the movement of glaciers. In genetics, melting DNA means to separate the double-stranded DNA into two single strands by heating or the use of chemical agents, cf. polymerase chain reaction. Melting Melting, or fusion, is a physical process that results in the phase transition of a substance

title: Transition metal

text: prevent d–d bonding, which again tends to differentiate them from the accepted transition metals. Mercury has a melting point of and is a liquid at room temperature. Transition metal In chemistry, the term transition metal (or transition element) has three possible meanings: English chemist Charles Bury (1890–1968) first used the word "transition" in this context in 1921, when he referred to a "transition series of elements" during the change of an inner layer of electrons (for example n=3 in the 4th row of the periodic table) from a stable group of 8 to one of 18, or from 18 to

title: Pot metal

text: copper, tin, magnesium, aluminium, iron, and cadmium. The primary advantage of pot metal is that it is quick and easy to cast. Because of its low melting temperature, it requires no sophisticated foundry equipment or specialized molds. Manufacturers sometimes use it to experiment with molds and ideas (e.g., prototypes) before casting final products in a higher quality alloy. Depending on the exact metals "thrown into the pot," pot metal can become unstable over time, as it has a tendency to bend, distort, crack, shatter, and pit with age. The low boiling point of zinc and fast cooling of newly cast

title: Post-transition metal

text: bismuth. Historically, the transition metal series "includes those elements of the Periodic Table which 'bridge the gap' between the very electropositive alkali and allkaline earth metals and the electronegative non-metals of the groups: nitrogen-phosphorus, oxygen-sulfur, and the halogens." Cheronis, Parsons and Ronneberg wrote that, "The transition metals of low melting point form a block in the Periodic Table: those of Groups II 'b' [zinc, cadmium, mercury], III 'b' [aluminium, gallium, indium, thallium], and germanium, tin and lead in Group IV. These metals all have melting points below 425 °C." Post-transition metal Post-transition metals are a set of metallic elements in

title: Melting-point depression

text: melting temperature for individual atoms from the sum of their cohesive bonds. As a result, the BOLS predicts the surface layers of a nanoparticle melt at lower temperatures than the bulk of the nanoparticle. The BOLS mechanism states that if one bond breaks the remaining neighbouring ones become shorter and stronger. The cohesive energy, or the sum of bond energy, of the less coordinated atoms determines the thermal stability including melting, evaporating and other phase transition. The lowered CN changes the equilibrium bond length between atoms near the surface of the nanoparticle. The bonds relax towards equilibrium lengths, increasing the

title: Melting-point depression

text: models predict melting of the nanoparticle surface prior to the bulk atoms. If the LDM is true, a solid nanoparticle should function over a greater temperature range than other models predict. The LDM assumes that the surface atoms of a nanoparticle dominate the properties of all atoms in the particle. The cohesive energy of the particle is identical for all atoms in the nanoparticle. The LDM represents the binding energy of a nanoparticles as function of the free energies of the volume and surface. Equation 4 gives the normalized, size dependent melting temperature of a material according to the liquid-drop

title: Melting-point depression

text: model. formula_4 Where: σ=solid-vapor interface energy The liquid shell nucleation model (LSN) predicts that a surface layer of atoms melts prior to the bulk of the particle. The melting temperature of a nanoparticle is a function of its radius of curvature according to the LSN. Large nanoparticles melt at greater temperatures as a result of their larger radius of curvature. The model calculates melting conditions as a function of two competing order parameters using Landau potentials. One order parameter represents a solid nanoparticle, while the other represents the liquid phase. Each of the order parameters is a function of particle

title: Pot metal

text: the caster adds other metals to the mix to strengthen the cast part, improve flow of the molten metal, or to reduce cost. With a low melting point of 419 °C (786 °F), zinc is often alloyed with other metals including lead, tin, aluminium, and copper. Pot metal is generally used for parts that are not subject to high stresses or torque. Items created from pot metal include toys, furniture fittings, tool parts, electronics components, automotive parts, inexpensive jewelry and improvised weaponry. It is also used in inexpensive electric guitars and other budget priced musical instruments. Pot metal Pot metal

title: Liquid metal ion source

text: Liquid metal ion source A liquid metal ion source (LMIS) is an ion source which uses metal that is heated to the liquid state and used to form an electrospray to form ions. An electrospray Taylor cone is formed by the application of a strong electric field and ions are produced by field evaporation at the sharp tip of the cone, which has a high electric field. Ions from a LMIS are used in ion implantation and in focused ion beam instruments. Typically gallium is preferred for its low melting point, low vapor pressure, its relatively unreactive nature, and because

title: Selective laser melting

text: This takes place inside a chamber containing a tightly controlled atmosphere of inert gas, either argon or nitrogen at oxygen levels below 500 parts per million. Once each layer has been distributed, each 2D slice of the part geometry is fused by selectively melting the powder. This is accomplished with a high-power laser beam, usually an ytterbium fiber laser with hundreds of watts. The laser beam is directed in the X and Y directions with two high frequency scanning mirrors. The laser energy is intense enough to permit full melting (welding) of the particles to form solid metal. The process

title: Selective laser melting

text: grouped selective laser melting into the category of "laser sintering", although this is an acknowledged misnomer because the process fully melts the metal into a solid homogeneous mass, unlike selective laser sintering (SLS) which is a true sintering process. Another name for Selective Laser Melting is Direct Metal Laser Sintering (DMLS), a name deposited by the EOS brand, however misleading on the real process because the part is being melted during the production, not sintered, which mean the part is fully dense. This process is in all points very similar to other SLM processes, and is often considered as a

title: Liquid metal embrittlement

text: depend upon the chemical compositions of the metal couple. External parameters like temperature, strain rate, stress and time of exposure to the liquid metal prior to testing affect LME. Temperature produces a ductility trough and a ductile to brittle transition behaviour in the solid metal. The temperature range of the trough as well as the transition temperature are altered by the composition of the liquid and solid metals, the structure of the solid metal and other experimental parameters. The lower limit of the ductility trough generally coincides with the melting point of the liquid metal. The upper limit is strain

title: Congruent melting

text: Congruent melting Congruent melting occurs during melting of a compound when the composition of the liquid that forms is the same as the composition of the solid. It can be contrasted with incongruent melting. This generally happens in two-component systems. To take a general case, let A and B be the two components and AB a stable solid compound formed by their chemical combination. If we draw a phase diagram for the system, we notice that there are three solid phases, namely A, B and compound AB. Accordingly, there will be three fusion or freezing point curves AC, BE and

title: Vacuum induction melting

text: crucible sometimes causes carbon contamination which causes some of the titanium ions to form titanium carbide (TiC). These TiC particles change the transformation temperature along with the strength of the alloy. This is one drawback with the process of vacuum induction melting in graphite. Vacuum induction melting Vacuum induction melting (VIM) utilizes electric currents to melt metal within a vacuum. The first prototype was developed in 1920. One of the only ways to induce a current within a conductor is through electromagnetic induction. Electromagnetic induction induces eddy currents within conductors by changing the magnetic field. Eddy currents create heating effects

title: Metal

text: per gram. Its ores are widespread; it is easy to refine; and the technology involved has been developed over hundreds of years. Cast iron is even cheaper, at a fraction of US$0.01 per gram, because there is no need for subsequent purification. Platinum, at a cost of about $27 per gram, may be the most ubiquitous given its very high melting point, resistance to corrosion, electrical conductivity, and durability. It is said to be found in, or used to produce, 20% of all consumer goods. Polonium is likely to be the most expensive metal, at a notional cost of about

title: Alkali metal

text: obtained the same way: sulfuric acid is first used to dissolve the desired alkali metal ion and aluminium(III) ions from the ore (leaching), whereupon basic precipitation removes aluminium ions from the mixture by precipitating it as the hydroxide. The remaining insoluble alkali metal carbonate is then precipitated selectively; the salt is then dissolved in hydrochloric acid to produce the chloride. The result is then left to evaporate and the alkali metal can then be isolated. Lithium and sodium are typically isolated through electrolysis from their liquid chlorides, with calcium chloride typically added to lower the melting point of the mixture.

title: Filler metal

text: avoided by controlling the distribution of heat over space, rather than limiting the maximum heat. If filler is used, it is of a similar alloy and melting point to the base metal. Not all welding processes require filler metal. Autogenous welding processes only require part of the existing base metal to be melted and this is sufficient, provided that the joint is already mechanically close-fitting before welding. Forge- or hammer welding uses hammering to close up the hot joint and also to locally increase its heat. Many gas welding processes, such as lead burning, are typically autogenous and a separate

title: Liquid metal embrittlement

text: it. The practical significance of liquid metal embrittlement is revealed by the observation that several steels experience ductility losses and cracking during hot-dip galvanizing or during subsequent fabrication. Cracking can occur catastrophically and very high crack growth rates have been measured. Similar metal embrittlement effects can be observed even in the solid state, when one of the metals is brought close to its melting point; e.g. cadmium-coated parts operating at high temperature. This phenomenon is known as solid metal embrittlement. Liquid metal embrittlement or LME is characterized by the reduction in the threshold stress intensity, true fracture stress or in

title: Hot metal gas forming

text: Hot metal gas forming Hot metal gas forming (HMGF) is a method of die forming in which a metal tube is heated to a pliable state, near to but below its melting point, then pressurized internally by a gas in order to form the tube outward into the shape defined by an enclosing die cavity. The high temperatures allow the metal to elongate, or stretch, to much greater degrees without rupture than are possible in previously utilized cold and warm forming methods. In addition, the metal can be formed into finer details and requires less overall forming force than traditional

title: Melting pot

text: what was done to the Mizrahi immigrants. Today the reaction to this doctrine is ambivalent; some say that it was a necessary measure in the founding years, while others claim that it amounted to cultural oppression. Others argue that the melting pot policy did not achieve its declared target: for example, the persons born in Israel are more similar from an economic point of view to their parents than to the rest of the population. The policy is generally not practised today though as there is less need for that—the mass immigration waves at Israel's founding have declined. Nevertheless, one

title: Alkali metal halide

text: temperatures above the melting point. The table below provides links to each of the individual articles for these compounds. The numbers beside the compounds show the electronegativity difference between the elements based on the Pauling scale. The higher the number is, the more ionic the solid is. Alkali metal halide Alkali metal halides (also known as alkali halides) are the family of inorganic compounds with the chemical formula MX, where M is an alkali metal and X is a halogen. These compounds are the often commercially significant sources of these metals and halides. The best known of these compounds is

title: Alkali metal halide

text: lattice that accommodates coordination number of eight for the larger metal cation (and the anion also). The alkali metal halides exist as colourless crystalline solids, although as finely ground powders appear white. They melt at high temperature, usually several hundred degrees to colorless liquids. Their high melting point reflects their high lattice energies. At still higher temperatures, these liquids evaporate to give gases composed of diatomic molecules. These compounds dissolve in polar solvents to give ionic solutions that contain highly solvated anions and cations. Alkali halides dissolve large amounts of the corresponding alkali metal: caesium is completely miscible at all

title: What Love Has Joined Together

text: What Love Has Joined Together "What Love Has Joined Together" is a song written and composed by Miracles members Smokey Robinson and Bobby Rogers, was recorded by five Motown acts: The Miracles, Mary Wells, The Temptations, Barbara McNair, and Syreeta, and was issued as B-sides to hits by Wells and The Temptations; "Your Old Standby" for Wells, released in 1963, and "It's Growing" by The Temptations, released in 1965. The song talks about a person professing their love to their loved one regardless of people's comments trying to separate them, with the person stressing the point that "what love has

title: Francium

text: has a half-life of 56 seconds, although synthetic astatine-210 is much longer-lived with a half-life of 8.1 hours. All isotopes of francium decay into astatine, radium, or radon. Francium-223 also has a shorter half-life than the longest-lived isotope of each synthetic element up to and including element 105, dubnium. Francium is an alkali metal whose chemical properties mostly resemble those of caesium. A heavy element with a single valence electron, it has the highest equivalent weight of any element. Liquid francium—if created—should have a surface tension of 0.05092 N/m at its melting point. Francium's melting point was calculated to be

title: Post-transition metal

text: of the post-transition metals. The small radius of the aluminium ion combined with its high charge make it a strongly polarizing species, prone to covalency. Aluminium in pure form is a soft metal (MH 3.0) with low mechanical strength. It has a close-packed structure (BCN 12) showing some evidence of partially directional bonding. It has a low melting point and a high thermal conductivity. Its strength is halved at 200 °C, and for many of its alloys is minimal at 300 °C. The latter three properties of aluminium limit its use to situations where fire protection is not required, or

title: The Melting Pot (restaurant)

text: The Melting Pot (restaurant) The Melting Pot is a chain of franchised fondue restaurants in the United States, Canada and Mexico. The Tampa, Florida based company has 167 locations . The Melting Pot menu contains various cheese fondues, wines, salads, entrees of meat and seafood served with dipping sauces and oil or broth to be cooked in, and chocolate fondues. It is part of Front Burner Brands. The first Melting Pot opened in April 1975 in Maitland, Florida – a suburban city of the Orlando Metropolitan Area – and served only three items on its menu. With permission from the

title: The Melting Pot (restaurant)

text: events. The Melting Pot (restaurant) The Melting Pot is a chain of franchised fondue restaurants in the United States, Canada and Mexico. The Tampa, Florida based company has 167 locations . The Melting Pot menu contains various cheese fondues, wines, salads, entrees of meat and seafood served with dipping sauces and oil or broth to be cooked in, and chocolate fondues. It is part of Front Burner Brands. The first Melting Pot opened in April 1975 in Maitland, Florida – a suburban city of the Orlando Metropolitan Area – and served only three items on its menu. With permission from

title: White metal

text: have good flow characteristics, have the ability to cast fine detail without an excessive amount of porosity and cast at between 230 °C and 300 °C (450 °F and 575 °F). In compliance with British law, the British fine art trade uses the term "white metal" in auction catalogues to describe foreign silver items which do not carry British Assay Office marks, but which are nonetheless understood to be silver and are priced accordingly. Tin-lead and tin-copper alloys such as Babbitt metal have a low melting point that is ideal for use as solder, but these alloys also have ideal

title: Glass-to-metal seal

text: absorb the stresses from thermal expansion mismatches. Due to its very low vapor pressure, indium finds use in glass-metal seals used in vacuum technology. Gallium is a soft metal with melting point at 30 °C. It readily wets glasses and most metals and can be used for seals that can be assembled/disassembled by just slight heating. It can be used as a liquid seal up to high temperatures or even at lower temperatures when alloyed with other metals (e.g. as galinstan). Mercury is a metal liquid at normal temperature. It was used as the earliest glass-to-metal seal and is still

title: The Incredible Melting Man

text: hospital back on Earth, with bandages covering his face; his physician, Dr. Loring (Lisle Wilson), cannot explain what is happening to West or how he survived the blast. After the doctor leaves, West awakens and is horrified to find the flesh on his face and hands melting away. Hysterical, he attacks and kills a nurse (Bonnie Inch), then escapes the hospital in a panic. Loring and Dr. Theodore "Ted" Nelson (DeBenning), a scientist and friend of West, discover that the nurse's corpse is emitting feeble radiation, and realize West's body has become radioactive. Nelson believes West has gone insane, and

title: Hot metal gas forming

text: be used in HMGF. In this case the die can be used not only as a shaping tool, but also as a tempering tool, so that the final hardness of the formed tube after forming and cooling is increased. The process is often called "press hardening" in this case. Hot metal gas forming Hot metal gas forming (HMGF) is a method of die forming in which a metal tube is heated to a pliable state, near to but below its melting point, then pressurized internally by a gas in order to form the tube outward into the shape defined by

title: Selective laser melting

text: is repeated layer after layer until the part is complete. The DMLS machine uses a high-powered 200 watt Yb-fiber optic laser. Inside the build chamber area, there is a material dispensing platform and a build platform along with a recoater blade used to move new powder over the build platform. The technology fuses metal powder into a solid part by melting it locally using the focused laser beam. Parts are built up additively layer by layer, typically using layers 20 micrometers thick. Many Selective Laser Melting (SLM) machines operate with a work space up to 400 mm (15.748 in) in

title: Selective laser melting

text: CAD programs) need further conversion to .cli & .sli files (the format required for non stereolithography machines). Software converts .stl file to .sli files, as with the rest of the process, there can be costs associated with this step. The typical components of a DMLS machine include: a laser, roller, sintering piston, removable build plate, supply powder, supply piston, and optics and mirrors. Selective laser melting Selective laser melting (SLM), also known as direct metal laser sintering (DMLS) or laser powder bed fusion (LPBF), is a rapid prototyping, 3D printing, or additive manufacturing (AM) technique designed to use a high

title: Metal foam

text: processes such as selective laser melting (SLM). Plates can be used as casting cores. The shape is customized for each application. This manufacturing method allows for "perfect" foam, so-called because it satisfies Plateau's laws and has conducting pores of the shape of a truncated octahedron Kelvin cell (body-centered cubic structure). Metal foam can be used in product or architectural composition. Foam metal has been used in experimental animal prosthetics. In this application, a hole is drilled into the bone and the metal foam inserted, letting the bone grow into the metal for a permanent junction. For orthopedic applications, tantalum or