834:(HIP) compresses and sinters the part simultaneously by applying heat on the order of 2300 °F (1250 °C), in the case of iron, or 2750 °F (1500 °C) in the case of nickel alloys. This procedure, together with explosion-driven compressive techniques is used extensively in the production of high-temperature and high-strength parts such as turbine disks for jet engines. In most applications of powder metallurgy the compact is hot-pressed, heated to a temperature above which the materials cannot remain work-hardened. Hot pressing lowers the pressures required to reduce porosity and speeds welding and grain deformation processes. It also permits better dimensional control of the product, lessens sensitivity to physical characteristics of starting materials, and allows powder to be compressed to higher densities than with cold pressing, resulting in higher strength. Negative aspects of hot pressing include shorter die life, slower throughput because of powder heating, and the frequent necessity for protective atmospheres or simple vacuum during forming and cooling stages.
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very little scrap metal and can be used to make many different shapes. The tolerances that this process can achieve in combination with sintering are very precise, ranging from +/- 0.008 inches (0.2 mm) for axial dimensions and +/- 0.020 inches (0.5 mm) for radial dimensions. This is the most efficient type of powder compacting (the following subcategories are also from this reference). This operation is generally only applicable on small production quantities, and although the cost of a mold is much lower than that of pressing dies, it is generally not reusable and the production time is much longer. Production rates are usually very low, but parts weighing up to 100 pounds can be effectively compacted. Because pressure is applied from all directions, lower compaction pressures are required to produce higher densities of powder in the end product.
278:(ECAS) technologies use electric currents to sinter powders. This reduces production time dramatically (it can take from 15 minutes to a few microseconds), does not require a long furnace heat, and allows near-theoretical densities, but it also has the drawback of simple shapes. Powders used in ECAS do not require binders because they can be directly sintered, without needing to be pre-pressed and compacted with binders. Moulds are designed for the final part shape since the powders sinter while filling the cavity under applied pressure. This avoids the problem of shape variations caused by non-isotropic sintering, as well as distortions caused by gravity at high temperatures. The most common of these technologies is
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666:) to 40,000 psi (280,000 kPa) for most metals and approximately 2,000 psi (14,000 kPa) to 10,000 psi (69,000 kPa) for non-metals. The density of isostatic compacted parts is 5% to 10% higher than with other powder metallurgy processes. Typical workpiece sizes range from 0.25 in (6.35 mm) to 0.75 in (19.05 mm) thick and 0.5 in (12.70 mm) to 10 in (254 mm) long. It is possible to compact workpieces that are between 0.0625 in (1.59 mm) and 5 in (127 mm) thick and 0.0625 in (1.59 mm) to 40 in (1,016 mm) long.
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atomization cools and solidifies the metal particles more rapidly than gas atomization. Since the solidification rate is inversely proportional to the particle size, smaller particles can be made using water atomization. The smaller the particles, the more homogeneous the microstructure will be. Particles produced this way will also have a more irregular shape and the particle size distribution will be wider. In addition, some surface contamination can occur by oxidation skin formation. Powder can be reduced by some kind of pre-consolidation treatment, such as annealing used for the manufacture of ceramic tools.
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253:, usually a metallic "can". The can is vibrated, then evacuated and sealed. To sinter the powder, it is placed in a hot "isostatic press" for several hours, where it is heated to around 0.7 times the melting point, and subjected to an external gas pressure of ~100 MPa. This results in a shaped part of full density with as-wrought or better properties. HIP was invented in the 1950-60s and entered tonnage production in the 1970-80s. In 2015, it was used to produce ~25,000 t/y of stainless and tool steels, as well as important parts of
292:(AM) is a relatively novel family of techniques that use metal powders (among other materials, such as plastics) to make parts by laser sintering or melting. The process was undergoing rapid growth as of 2015, and as of 2018 has been used predominantly for research, prototyping or advanced applications in the aerospace industry, though also in the biomedical, defence and automotive industries. It has been used in the aerospace industry because traditional processes are more time-consuming, difficult, and costly. Processes include
516:) and control over the size distribution of the metal particles produced is rather poor. Other techniques such as nozzle vibration, nozzle asymmetry, multiple impinging streams, or molten-metal injection into ambient gas are all available to increase atomization efficiency, produce finer grains, and to narrow the particle size distribution. Unfortunately, it is difficult to eject metals through orifices smaller than a few millimeters in diameter, which in practice limits the minimum size of powder grains to approximately
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electrolyzing metal-containing solutions, and mechanical crushing, as well as more complicated methods, including a variety of ways to fragment liquid metal into droplets, and condensation from metal vapor. Compaction is usually done with a die press, but can also be done with explosive shocks or placing a flexible container in a high-pressure gas or liquid. Sintering is usually done in a dedicated furnace, but can also be done in tandem with compression (hot isostatic compression), or with the use of electric currents.
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above the melting point of a component in the powder metal part, the liquid of the melted particles fills the pores. This type of sintering is known as liquid-state sintering. A major challenge with sintering in general is knowing the effect of the process on the dimensions of the compact particles. This is especially difficult for tooling purposes in which specific dimensions may be needed. It is most common for the sintered part to shrink and become denser, but it can also expand or experience no net change.
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electrode from which an arc is established which heats the metal rod. As the tip material fuses, the rapid rod rotation throws off tiny melt droplets which solidify before hitting the chamber walls. A circulating gas sweeps particles from the chamber. Similar techniques could be employed in space or on the Moon. The chamber wall could be rotated to force new powders into remote collection vessels, and the electrode could be replaced by a solar mirror focused at the end of the rod.
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techniques, but they can be divided into two main categories: resistance sintering techniques, which apply lower voltages and currents and take on the from around ten seconds to ten minutes; and electric discharge sintering, which use capacitor banks to achieve higher currents and voltages, and take from tens of microseconds to tens of milliseconds. Resistance sintering techniques include
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zone as it prevents oxidation from immediate contact with the air or a phenomenon known as rapid cooling. All of the three stages must be carried out in a controlled atmosphere containing no oxygen. Hydrogen, nitrogen, dissociated ammonia, and cracked hydrocarbons are common gases pumped into the furnace zones providing a reducing atmosphere, preventing oxide formation.
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powders is accomplished through electric currents, usually with a characteristic processing time of 15 to 30 minutes. On the other hand, electric discharge sintering methods rely on high-density currents (from 0.1 to 1 kA/mm^2) to directly sinter electrically conductive powders, with a characteristic time between tens of microseconds to hundreds of milliseconds.
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208:. Compaction of the powder in the die is generally performed at room temperature. Sintering is the process of binding a material together with heat without liquefying it. It is usually conducted at atmospheric pressure and under carefully controlled atmosphere composition. To obtain special properties or enhanced precision, secondary processing like
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to 10.16 cm) in length. However, it is possible to produce parts that are less than 0.1 square inches (0.65 cm) and larger than 25 square inches (160 cm). in area and from a fraction of an inch (2.54 cm) to approximately 8 inches (20 cm) in length. Small mechanical presses can generally compact about 100 pieces per minute.
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materials. If the temperature of the compact parts is raised too quickly, the air in the pores will be at a very high internal pressure which could lead to expansion or fracture of the part. The second zone, known as the high-temperature stage, is used to produce solid-state diffusion and particle bonding. The material is seeking to lower its
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428:-coated tungsten). The surface strain of the thin layer places the harder metal under compression, so that when the entire composite is sintered the rupture strength increases markedly. With this method, strengths on the order of 2.8 GPa versus 550 MPa have been observed for, respectively, coated (25% cobalt) and uncoated
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workpiece with an explosively accelerated plate. Despite being researched for a long time, the technique still has some problems in controllability and uniformity. However, it offers some valuable potential advantages. As an example, consolidation occurs so rapidly that metastable microstructures may be retained.
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For softer, easier-to-form metals such as aluminium and copper alloys continuous extrusion may also be performed using processes such as conform or continuous rotary extrusion. These processes use a rotating wheel with a groove around its circumference to drive the loose powder through a forming die.
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at room temperature; in the other, the powder is extruded at elevated temperatures without fortification. Extrusions with binders are used extensively in the preparation of tungsten-carbide composites. Tubes, complex sections, and spiral drill shapes are manufactured in extended lengths and diameters
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Powders can also be rolled to produce sheets. The powdered metal is fed into a two-high rolling mill, and is compacted into strip form at up to 100 feet per minute (0.5 m/s). The strip is then sintered and subjected to another rolling and further sintering. Rolling is commonly used to produce
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In a simple compression process, powder flows from a bin onto a two-walled channel and is repeatedly compressed vertically by a horizontally stationary punch. After stripping the compress from the conveyor, the compacted mass is introduced into a sintering furnace. An even easier approach is to spray
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These techniques employ electric currents to drive or enhance sintering. A combination of mechanical pressure and electrical current, passed through either the powder or the container, significantly reduces the sintering time compared to conventional solutions. There are many classifications of these
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for metal powder compaction. To attain the same compression ratio across a component with more than one level or height, it is necessary to work with multiple lower punches. A cylindrical workpiece is made by single-level tooling. A more complex shape can be made by the common multiple-level tooling.
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The density of the compacted powder increases with the amount of pressure applied. Typical pressures range from 80 psi to 1000 psi (0.5 MPa to 7 MPa), pressures from 1000 psi to 1,000,000 psi have been obtained. Pressure of 10 t/in to 50 t/in (150 MPa to 700 MPa) are commonly used
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Another powder-production technique involves a thin jet of liquid metal intersected by high-speed streams of atomized water which break the jet into drops and cool the powder before it reaches the bottom of the bin. In subsequent operations the powder is dried. This is called water atomization. Water
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Powder can be obtained through gas or water atomization, centrifugal atomization, chemically reducing particulate compounds, electrolytic deposition in appropriate conditions, simple pulverization and grinding, thermal decomposition of particulate hydrides or carbonyls, precipitation out of solution,
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Any fusible material can be atomized. Several techniques have been developed that permit large production rates of powdered particles, often with considerable control over the size ranges of the final grain population. Powders may be prepared by crushing, grinding, chemical reactions, or electrolytic
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is an excess of surface-free energy. The process of solid-state sintering is complex and dependent on the material and furnace (temperature and gas) conditions. There are six main stages that sintering processes can be grouped in which may overlap with one another: 1 initial bonding among particles,
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In die compaction, there are four major classes of tool styles: single-action compaction, used for thin, flat components; opposed double-action with two punch motions, which accommodates thicker components; double-action with floating die; and double-action withdrawal die. Double action classes give
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One of the major advantages of this process is its ability to produce complex geometries. Parts with undercuts and threads require a secondary machining operation. Typical part sizes range from 0.1 square inches (0.65 cm) to 20 square inches (130 cm). in area and from 0.1 to 4 inches (0.25
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techniques. Controllable characteristics of products prepared using various powder technologies include mechanical, magnetic, and other unconventional properties of such materials as porous solids, aggregates, and intermetallic compounds. Competitive characteristics of manufacturing processing (e.g.
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and does so by moving toward the points of contact between particles. The contact points become larger and eventually a solid mass with small pores is created. The third zone, also called the cooling period, is used to cool down the parts while still in a controlled atmosphere. This is an important
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Isostatic tools are available in three styles, free mold (wet-bag), coarse mold (damp-bag), and fixed mold (dry-bag). The free mold style is the traditional style of isostatic compaction and is not generally used for high production work. In free mold tooling the mold is removed and filled outside
674:, reliefs, threads, and cross holes. No lubricants are needed for isostatic powder compaction. The minimum wall thickness is 0.05 inches (1.27 mm) and the product can have a weight between 40 and 300 pounds (18 and 136 kg). There is 25 to 45% shrinkage of the powder after compacting.
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Isostatic powder compacting is an alternate method of powder compaction. In cold isostatic compaction, fine metal particles are placed into a flexible mould, which is then immersed in a high-pressure gas or liquid from all directions (isostatic). After sintering, this manufacturing process produces
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and intermetallic phases. As the pore sizes decrease, the density of the material will increase. As stated above, this shrinkage is a huge problem in making parts or tooling in which particular dimensions are required. The shrinkage of test materials is monitored and used to manipulate the furnace
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is a process in which particles under pressure chemically bond to themselves in order to form a coherent shape when exposed to a high temperature. The temperature in which the particles are sintered is most commonly below the melting point of the main component in the powder. If the temperature is
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The dominant technology for the forming of products from powder materials, in terms of both tonnage quantities and numbers of parts produced, is die pressing. There are mechanical, servo-electrical and hydraulic presses available in the market, whereby the biggest powder throughput is processed by
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Powder compaction, one of the most critical steps in powder metallurgy processes, is the process of compacting metal powder through the application of high pressures. Most powder compaction is done with mechanical presses and rigid tools, but hydraulic and pneumatic techniques can also be used, as
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One of the older such methods is the process of blending fine (<180 microns) metal powders with additives, pressing them into a die of the desired shape, and then sintering the compressed material together, under a controlled atmosphere. The metal powder is usually iron, and additives include a
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There appears to be no limitation to the variety of metals and alloys that can be extruded, provided the temperatures and pressures involved are within the capabilities of die materials. Extrusion lengths may range from 3 to 30 m and diameters from 0.2 to 1 m. Modern presses are largely
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Typically the tools are held in the vertical orientation with the punch tool forming the bottom of the cavity. Probably the most basic consideration is being able to remove the part from the die after it is pressed, along with avoiding sharp corners in the design. Keeping the maximum surface area
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Strictly, the phrase "continuous process" should be used only to describe modes of manufacturing which could be extended indefinitely in time. Normally, however, the term refers to processes whose products are much longer in one physical dimension than in the other two. Compression, rolling, and
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Resistance sintering voltages usually reach about 1 kA per square centimer, while electric discharge sintering voltages require very high voltages, over 10 kA per square centimer. Resistance sintering techniques are consolidation methods based on temperature, where heating of the mold and of the
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An alternative approach capable of producing a very narrow distribution of grain sizes but with low throughput consists of a rapidly spinning bowl heated to well above the melting point of the material to be powdered. Liquid metal, introduced onto the surface of the basin near the center at flow
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are intimately related to each other. Sintering involves the production of a hard solid metal or ceramic piece from a starting powder. The ancient Incas made jewelry and other artifacts from precious metal powders, though mass manufacturing of PM products did not begin until the mid or late 19th
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into a mould to form a "green" (with binder) part of complex geometry. This part is then heated or otherwise treated to remove the binder to give a "brown" (without binder) part. This part is then sintered and shrinks by ~18% to give a complex and 95–99% dense finished part (surface roughness ~3
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Shock consolidation, or dynamic consolidation, is an experimental technique of consolidating powders using high pressure shock waves. This technique is useful for very large products, including those over 3000 tons and larger than 100 square inches. These are commonly produced by impacting the
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Centrifugal disintegration of molten particles offers one way around these problems. Extensive experience is available with iron, steel, and aluminium. Metal to be powdered is formed into a rod which is introduced into a chamber through a rapidly rotating spindle. Opposite the spindle tip is an
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Atomization is accomplished by forcing a molten metal stream through an orifice at moderate pressures. A gas is introduced into the metal stream just before it leaves the nozzle, serving to create turbulence as the entrained gas expands (due to heating) and exits into a large collection volume
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furnaces contain three zones with three different properties that help to carry out the six steps above. The first zone, commonly coined the burn-off or purge stage, is designed to combust air, burn any contaminants such as lubricant or binders, and slowly raise the temperature of the compact
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which can exist for specific compositions. In addition, whole body melting of starting materials is required for alloying, thus imposing unwelcome chemical, thermal, and containment constraints on manufacturing. Unfortunately, the handling of aluminium/iron powders poses major problems. Other
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in manufacturing, lowering material losses and reducing the cost of the final product. This occurs especially often with small metal parts, like gears for small machines. Some porous products, allowing liquid or gas to permeate them, are produced in this way. They are also used when melting a
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Powder metallurgy techniques usually consist of the compression of a powder, and heating (sintering) it at a temperature below the melting point of the metal, to bind the particles together. Powder for the processes can be produced in a number of ways, including reducing metal compounds,
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The special materials and processes used in powder metallurgy can pose hazards to life and property. The high surface-area-to-volume ratio of the powders can increase their chemical reactivity in biological exposures (for example, inhalation or ingestion), and increases the risk of
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Through a combination of high pressure and a complex strain path the powder particles deform, generate a large amount of frictional heat and bond together to form a bulk solid. Theoretically, fully continuous operation is possible as long as the powder can be fed into the process.
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HIP produces products often of higher quality than other processes. However, HIP is expensive, and generally unnattractive for high-volume production, due to the high cost of placing the powder in a flexible isolating medium that can withstand the temperatures and pressures
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powder onto a moving belt and sinter it without compression. However, good methods for stripping cold-pressed materials from moving belts are hard to find. One alternative that avoids the belt-stripping difficulty altogether is the manufacture of metal sheets using opposed
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1011:. Materials considered relatively benign in bulk can pose special toxicological risks when in a finely divided form. Inhalation of heavy metals can result in many health issues. Lead and cadmium are generally toxic, and cobalt can cause
232:. This produces precise parts, normally very close to the die dimensions, but with 5–15% porosity, and thus sub-wrought steel properties. This method is still used to make around 1 Mt/y of structural components of iron-based alloys.
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varying in the range 0.5–300 mm (0.020–11.811 in). Hard metal wires of 0.1 mm (0.0039 in) diameter have been drawn from powder stock. At the opposite extreme, large extrusions on a tonnage basis may be feasible.
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In powder metallurgy or ceramics it is possible to fabricate components which otherwise would decompose or disintegrate. All considerations of solid-liquid phase changes can be ignored, so powder processes are more flexible than
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much better density distribution than single action. Tooling must be designed so that it will withstand the extreme pressure without deforming or bending. Tools must be made from materials that are polished and wear-resistant.
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below 20 square inches (0.013 m) and the height-to-diameter ratio below 7-to-1 is recommended. Along with having walls thicker than 0.08 inches (2.0 mm) and keeping the adjacent wall thickness ratios below 2.5-to-1.
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Compaction of the powder within the die with punches to form the compact. Generally, compaction pressure is applied through punches from both ends of the toolset in order to reduce the level of density gradient within the
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Advantages over standard powder compaction are the possibility of thinner walls and larger workpieces. The height-to-diameter ratio has no limitation. No specific limitations exist in wall thickness variations,
512:. At low Re the liquid jet oscillates, but at higher velocities the stream becomes turbulent and breaks into droplets. Pumping energy is applied to droplet formation with very low efficiency (on the order of
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the canister. Damp bag is where the mold is located in the canister, yet filled outside. In fixed mold tooling, the mold is contained within the canister, which facilitates automation of the process.
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Extremely thin films and tiny spheres exhibit high strength. One application of this observation is to coat brittle materials in whisker form with a submicrometre film of much softer metal (e.g.
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Erik
Lassner, Wolf-Dieter Schubert, Eberhard Lüderitz, Hans Uwe Wolf, "Tungsten, Tungsten Alloys, and Tungsten Compounds" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim.
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Simple atomization techniques are available in which liquid metal is forced through an orifice at a sufficiently high velocity to ensure turbulent flow. The usual performance index used is the
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well as methods that combine compaction with sintering, like hot isostatic compaction. Traditional metalforming processes, including rolling, forging, extrusion, and swaging, are also used.
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century. In these early manufacturing operations, iron was extracted by hand from a metal sponge following reduction and was then reintroduced as a powder for final melting or sintering.
480:, atomizing the material. Various chemical and flame-associated powdering processes are adopted in part to prevent serious degradation of particle surfaces by atmospheric oxygen.
169:. Tungsten carbide is used to cut and form other metals and is made from tungsten carbide particles bonded with cobalt. Tungsten carbide is the largest and most important use of
520:. Atomization also produces a wide spectrum of particle sizes, necessitating downstream classification by screening and remelting a significant fraction of the grain boundary.
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exterior to the orifice. The collection volume is filled with gas to promote further turbulence of the molten metal jet. Air and powder streams are segregated using gravity or
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are heated in a controlled atmosphere in a process known as sintering. During this process, the surfaces of the particles are bonded and desirable properties are achieved.
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Orrù, Roberto (2009-02-12). "Materials
Science and Engineering: R: Reports : Consolidation/synthesis of materials by electric current activated/assisted sintering".
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2) neck growth, 3) pore channel closure, 4) pore rounding, 5) densification or pore shrinkage, and 6) pore coarsening. The main mechanisms present in these stages are
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In this way, powder metallurgy can be used to make unique materials impossible to get from melting or forming in other ways. A very important product of this type is
1082:"Two-high" means there are two wheels involved in the rolling. "Three-high" would involve three wheels rolling in different directions stacked on top of each other.
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rates adjusted to permit a thin metal film to skim evenly up the walls and over the edge, breaks into droplets, each approximately the thickness of the film.
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material is impractical, due to it having a high melting point, or an alloy of two mutually insoluble materials, such as a mixture of copper and graphite.
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for the construction industry. As of 2018, only hot pressing and, in a more limited way, spark plasma sintering had achieved direct industrial application.
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Vassiliou, Marius; Rhodes, C. G.; Mitchell, M. R.; Graves, J. A. (1989). "Metastable
Microstructure in Dynamically Consolidated γ Titanium Aluminide".
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Khan, M. K. (April 1980). "The
Importance of Powder Particle Size and Flow Behavior in the Production of P/M Parts for Soft Magnetic Applications".
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hydraulic presses. This forming technology involves the production cycle below, which offers a readily automated and high production rate process:
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Removal of the compact from the upper face of the die using the fill shoe in the fill stage of the next cycle, or an automation system or robot.
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microns). Invented in the 1970s, production has increased since 2000 with an estimated global volume in 2014 of 12,000 t worth €1265 million.
1993:
R. M. German, "Powder
Metallurgy and Particulate Materials Processing," Metal Powder Industries Federation, Princeton, New Jersey, 2005.
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867:(SPS), plasma-activated sintering (PAS), and pulse electric current sintering (PECS). electric discharge sintering techniques include
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Powders of the elements titanium, vanadium, thorium, niobium, tantalum, calcium, and uranium have been produced by high-temperature
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The powder metallurgy "press and sinter" process generally consists of three basic steps: powder blending (or pulverisation),
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and other metal additive manufacturing processes are a new category of commercially important powder metallurgy applications.
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Yurlova, M. S. (2014). "Journal of
Materials ScienceElectric pulse consolidation: an alternative to spark plasma sintering".
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871:. Currently, spark plasma sintering is currently the most commonly used method of electric pulse consolidation in general.
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filaments made with powder technology; linings for friction brakes; metal glasses for high-strength films and ribbons;
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472:. Exceedingly fine particles also have been prepared by directing a stream of molten metal through a high-temperature
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Makhlouf, M. M.; Mould, A. M.; Merchant, H. D. (July 1979). "Sintering of
Chemically Preconditioned Tin Powder".
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Spark plasma sintering, a kind of electric current assisted sintering that involves neither sparks nor plasma
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G. S. Upadhyaya, "Sintered
Metallic and Ceramic Materials" John Wiley and Sons, West Sussex, England, 2000
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F. Thummler and R.Oberacker "An
Introduction to Powder Metallurgy" The Institute of Materials, London 1993
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263:(MIM): Here the powder, normally very fine (<25 microns) and spherical, is mixed with plastic or wax
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There are several other PM processes that have been developed over the last fifty years. These include:
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of the material. If different elemental powders are compact and sintered, the material would form into
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Many special products are possible with powder metallurgy technology. A non-exhaustive list includes Al
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The head of a silver medallion commemorating the 4th international powder metallurgy conference in 1973
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conditions or to oversize the compact materials in order to achieve the desired dimensions. Although,
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for spacecraft reentry into Earth's atmosphere; electrical contacts for handling large current flows;
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1335:"Additive manufacturing (3D printing): A review of materials, methods, applications and challenges"
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Ngo, Tuan D.; Kashani, Alireza; Imbalzano, Gabriele; Nguyen, Kate T. Q.; Hui, David (2018-06-15).
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Powder forging: A "preform" made by the conventional "press and sinter" method is heated and then
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Extrusion processes are of two general types. In one type, the powder is mixed with a binder or
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Programmable sintering furnace with a controllable temperature program, used to sinter ceramics
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Filling a die cavity with a known volume of the powder feedstock, delivered from a fill shoe.
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whiskers coated with very thin oxide layers for improved refraction; iron compacts with Al
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Hydraulic cylinders, or hydraulic rams, used in the hot press of a particle board machine
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Ejection of the compact from the die, using the lower punch(es) withdrawal from the die.
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deposition. The most commonly used powders are copper-base and iron-base materials.
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A much wider range of products can be obtained from powder processes than from direct
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filters, porous oil-impregnated bearings, electrical contacts and diamond tools.
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During this process, a number of characteristics are increased including the
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APMI International "The Global
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tool wear, complexity, or vendor options) also may be closely controlled.
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substances that are especially reactive with atmospheric oxygen, such as
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366:
358:
326:
240:
157:. PM processes are sometimes used to reduce or eliminate the need for
2024:
1665:
Vreeland, T.; Kasiraj, P.; Ahrens, Thomas J.; Schwarz, R. B. (1983).
1012:
444:
Closeup image of copper powder produced via gas atomization using air
425:
403:
229:
225:
221:
353:, are sinterable in special atmospheres or with temporary coatings.
267:
to near the maximum solid loading, typically around 65% volume, and
913:
184:
Since the advent of industrial production-scale metal powder-based
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891:
853:
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771:
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439:
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173:, consuming about 50% of the world supply. Other products include
131:
2010:
Rapid manufacturing technique developed at the KU Leuven, Belgium
1460:
Sheasby, J. S. (Oct 1979). "Powder Metallurgy of Iron-Aluminum".
922:
sheet metal for electrical and electronic components, as well as
1446:
923:
243:
to full density, resulting in practically as-wrought properties.
970:
350:
29:
963:
automatic and operate at high speeds (on the order of m/s).
704:
Cross section of sintering tool along with the sintered part
827:
Microstructure of nickel alloy after hot isostatic pressing
325:
The history of powder metallurgy and the art of metal and
1667:"Shock Consolidation of Powders - Theory and Experiment"
1701:"An improved method for shock consolidation of powders"
1640:
1638:
1636:
1634:
1632:
1630:
1628:
1626:
1624:
1622:
987:
394:
coatings for improved high-temperature creep strength;
1760:
PICKPM.COM: A Powder Metallurgy Information Resource
1439:
Freitas, R. A.; Gilbreath, W. P. (1 November 1982).
1982:An earlier version of this article was copied from
60:. Unsourced material may be challenged and removed.
1644:Todd, Robert H., Allen, Dell K., Alting, Leo1994
650:Isostatically pressed nickel alloy test specimens
2015:Slow motion video images of metal atomization at
340:of fused materials. In melting operations, the "
1572:
1570:
1568:
1566:
1564:
1562:
1560:
1558:
1556:
1554:
1525:. Archived from the original on August 6, 2020
1805:Materials Science and Engineering: R: Reports
1787:. Cambridge International Science Publishing.
8:
1500:Intern. J. Powder Metallurgy and Powder Tech
1481:Intern. J. Powder Metallurgy and Powder Tech
1462:Intern. J. Powder Metallurgy and Powder Tech
938:Die set used in extrusion of aluminum tubing
658:Compacting pressures range from 15,000
484:and also condensation from vaporized metal.
1034:Global Powder Metallurgy Property Database
842:) and then removing it from that medium (
120:Learn how and when to remove this message
1941:Materials and Processes in Manufacturing
1261:, European Powder Metallurgy Association
884:extrusion are the most common examples.
491:
1798:
1796:
1794:
1646:Manufacturing Processes Reference Guide
1291:"A faster FAST: Electro-Sinter-Forging"
1094:
1075:
726:The main driving force for solid-state
1988:Advanced Automation for Space Missions
1898:"Health Hazards and Powder Metallurgy"
1609:
1607:
1605:
1536:
1442:Advanced Automation for Space Missions
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1990:, a NASA report in the public domain.
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1370:
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1328:
1326:
1324:
1171:"Tungsten Statistics and Information"
779:does not deplete the compact part of
576:Diagram of stages of grain compaction
7:
1230:
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1226:
1224:
1222:
1220:
1175:National Minerals Information Center
1116:
1114:
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1100:
1098:
557:
533:
58:adding citations to reliable sources
1648:, Industrial Press Inc., New York,
850:Electric current assisted sintering
276:Electric current assisted sintering
696:Two grains being sintered together
27:Process of sintering metal powders
25:
1699:Meyers, M.A.; Wang, S.L. (1988).
1351:10.1016/j.compositesb.2018.02.012
946:Set of extruded aluminum sections
496:Diagram of an atomization process
1272:"Powder production technologies"
974:
34:
1289:Fais, Alessandro (2018-03-01).
45:needs additional citations for
1339:Composites Part B: Engineering
1177:. U.S. Geological Survey. 2024
417:which can be infiltrated with
282:, which has been used to make
1:
869:capacitor discharge sintering
1896:Kipling, M. D. (July 1976).
1883:
1871:
1839:Journal of Materials Science
1785:Powder Metallurgy Technology
1747:10.1016/0036-9748(89)90362-1
1720:10.1016/0001-6160(88)90147-2
1613:
1576:
1246:
1234:
1211:
879:Continuous powder processing
2026:, a non-profit organization
2066:
1817:10.1016/j.mser.2008.09.003
1519:"Define Powder Metallurgy"
1307:10.1016/j.mprp.2017.06.001
1019:in sensitive individuals.
816:
685:
1851:10.1007/s10853-013-7805-8
1543:: CS1 maint: unfit URL (
1049:Selective laser sintering
787:General sintering furnace
642:Cold isostatic compaction
413:; filters for gases; and
298:selective laser sintering
190:selective laser sintering
1947:(10th ed.). Wiley.
1783:Upadhyaya, G.S. (1996).
1276:Powder Metallurgy Review
1200:10.1002/14356007.a27_229
917:Diagram of metal rolling
313:History and capabilities
261:Metal injection moulding
1938:DeGarmo, E. P. (2008).
1150:Encyclopedia Britannica
1126:Encyclopedia Brittanica
1044:Selective laser melting
1039:Mechanical powder press
597:Powder compaction press
534:centrifugal atomization
302:selective laser melting
1914:10.1093/occmed/26.3.81
1059:Spark plasma sintering
1029:Electro sinter forging
947:
939:
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865:spark plasma sintering
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832:Hot isostatic pressing
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819:Hot isostatic pressing
813:Hot isostatic pressing
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524:Centrifugal techniques
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290:Additive manufacturing
247:Hot isostatic pressing
186:additive manufacturing
143:
1902:Occupational Medicine
1259:EPMA Key Figures 2015
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456:of the corresponding
443:
320:
306:electron beam melting
159:subtractive processes
139:is commonly used for
135:
1735:Scripta Metallurgica
768:thermal conductivity
54:improve this article
2045:Ceramic engineering
1686:10.1557/PROC-28-139
1295:Metal Powder Report
1122:"Powder metallurgy"
749:plastic deformation
633:Shock consolidation
503:cyclonic separation
69:"Powder metallurgy"
1765:2016-07-12 at the
1146:"Tungsten carbide"
986:. You can help by
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710:powdered materials
708:After compaction,
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446:
323:
144:
1741:(10): 1791–1794.
1708:Acta Metallurgica
1517:Jaiswal, Vishal.
1004:
1003:
568:Powder compaction
558:water atomization
548:Water atomization
436:Powder production
430:tungsten carbides
269:injection moulded
147:Powder metallurgy
130:
129:
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16:(Redirected from
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1957:. Archived from
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374:Special products
257:for jet engines.
204:compaction, and
167:tungsten carbide
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2019:Ames Laboratory
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1977:Further reading
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510:Reynolds number
490:
488:Gas atomization
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220:lubricant wax,
216:often follows.
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28:
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18:Cold compaction
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65:Find sources:
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49:
48:
43:This article
41:
37:
32:
31:
19:
2040:Metalworking
1987:
1966:. Retrieved
1959:the original
1940:
1908:(3): 81–84.
1905:
1901:
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1527:. Retrieved
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1301:(2): 80–86.
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1207:
1190:
1179:. Retrieved
1174:
1165:
1154:. Retrieved
1152:. 2024-06-03
1149:
1140:
1129:. Retrieved
1125:
1078:
1005:
992:
988:adding to it
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920:
899:
882:
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843:
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836:
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737:condensation
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400:heat shields
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90:
83:
76:
64:
52:Please help
47:verification
44:
1984:Appendix 4C
1345:: 172–196.
952:plasticizer
888:Compression
733:evaporation
304:(SLM), and
294:3D printing
255:superalloys
137:Iron powder
2034:Categories
1968:2019-10-09
1181:2024-07-04
1156:2024-07-04
1131:2024-07-04
1090:References
518:10 μm
419:lubricants
396:light bulb
342:phase rule
241:hot forged
110:April 2009
80:newspapers
1859:137613369
1529:6 January
1359:1359-8368
1315:0026-0657
1054:Sintering
995:July 2015
930:Extrusion
844:decanning
801:sintering
777:sintering
764:toughness
760:ductility
745:diffusion
743:, volume
728:sintering
716:Sintering
688:Sintering
682:Sintering
672:undercuts
454:reduction
408:microwave
363:extrusion
330:sintering
228:, and/or
206:sintering
141:sintering
1886:, p. 407
1874:, p. 406
1763:Archived
1616:, p. 464
1579:, p. 462
1539:cite web
1249:, p. 472
1214:, p. 473
1023:See also
1017:fibrosis
781:porosity
756:strength
610:compact.
470:formates
466:oxalates
462:carbides
458:nitrides
415:bearings
411:ferrites
338:alloying
196:Overview
175:sintered
171:tungsten
2050:Powders
1884:DeGarmo
1872:DeGarmo
1614:DeGarmo
1577:DeGarmo
1247:DeGarmo
1235:DeGarmo
1212:DeGarmo
967:Hazards
909:Rolling
840:canning
476:jet or
404:magnets
367:forging
359:casting
327:ceramic
300:(SLS),
210:coining
94:scholar
1951:
1922:957627
1920:
1857:
1652:
1357:
1313:
1013:asthma
772:alloys
747:, and
474:plasma
426:cobalt
346:phases
308:(EBM).
265:binder
230:nickel
226:copper
222:carbon
96:
89:
82:
75:
67:
1962:(PDF)
1945:(PDF)
1855:S2CID
1704:(PDF)
1670:(PDF)
1070:Notes
924:coins
799:Most
478:flame
365:, or
251:mould
101:JSTOR
87:books
2017:the
1949:ISBN
1918:PMID
1650:ISBN
1545:link
1531:2020
1447:NASA
1355:ISSN
1311:ISSN
1015:and
468:and
460:and
73:news
1986:of
1910:doi
1847:doi
1813:doi
1743:doi
1716:doi
1682:doi
1347:doi
1343:143
1303:doi
1196:doi
990:.
718:of
664:kPa
660:psi
351:tin
212:or
202:die
56:by
2036::
1916:.
1906:26
1904:.
1900:.
1853:.
1843:49
1841:.
1825:^
1809:63
1807:.
1793:^
1773:^
1739:23
1737:.
1712:36
1710:.
1706:.
1680:.
1678:28
1676:.
1672:.
1621:^
1584:^
1553:^
1541:}}
1537:{{
1521:.
1504:16
1502:.
1485:15
1483:.
1466:15
1464:.
1445:.
1367:^
1353:.
1341:.
1337:.
1323:^
1309:.
1299:73
1297:.
1293:.
1274:.
1219:^
1173:.
1148:.
1124:.
1097:^
762:,
758:,
751:.
739:,
735:,
514:1%
505:.
432:.
421:.
406:;
361:,
296:,
224:,
151:PM
1971:.
1924:.
1912::
1861:.
1849::
1819:.
1815::
1749:.
1745::
1722:.
1718::
1688:.
1684::
1547:)
1533:.
1449:.
1361:.
1349::
1317:.
1305::
1278:.
1202:.
1198::
1184:.
1159:.
1134:.
997:)
993:(
838:(
392:3
390:O
388:2
384:3
382:O
380:2
149:(
123:)
117:(
112:)
108:(
98:·
91:·
84:·
77:·
50:.
20:)
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