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Ingot
An ingot is a piece of relatively pure material, usually metal, that is cast into a shape suitable for further processing. In steelmaking, it is the first step among semi-finished casting products. Ingots usually require a second procedure of shaping, such as cold/hot working, cutting, or milling to produce a useful final product. Non-metallic and semiconductor materials prepared in bulk form may also be referred to as ingots, particularly when cast by mold based methods. Precious metal ingots can be used as currency (with or without being processed into other shapes), or as a currency reserve, as with gold bars. Types Ingots are generally made of metal, either pure or alloy, heated past its melting point and cast into a bar or block using a mold chill method. A special case are polycrystalline or single crystal ingots made by pulling from a molten melt. Single crystal Single crystal ingots (called boules) of materials are grown (crystal growth) using methods such as the Czo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxhide Ingot
Oxhide ingots are heavy (20-30 kg) metal slabs, usually of copper but sometimes of tin, produced and widely distributed during the Mediterranean Late Bronze Age (LBA). Their shape resembles the hide of an ox with a protruding handle in each of the ingot’s four corners. Early thought was that each ingot was equivalent to the value of one ox. However, the similarity in shape is simply a coincidence. The ingots' producers probably designed these protrusions to make the ingots easily transportable overland on the backs of pack animals. Complete or partial oxhide ingots have been discovered in Sardinia, Crete, Peloponnese, Cyprus, Cannatello in Sicily, Boğazköy in Turkey (ancient Hattusa, the Hittite capital), Qantir in Egypt (ancient Pi-Ramesses), and Sozopol in Bulgaria. Archaeologists have recovered many oxhide ingots from two shipwrecks off the coast of Turkey (one off Uluburun and one in Cape Gelidonya). Context The appearance of oxhide ingots in the archaeological record co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Semi-finished Casting Products
Semi-finished casting products are intermediate castings produced in a steel mill that need further processing before being finished goods. There are four types: ''ingots'', ''blooms'', ''billets'', and ''slabs''. Ingot Ingots are large rough castings designed for storage and transportation. The shape usually resembles a rectangle or square with generous fillets. They are tapered, usually with the big-end-down. Bloom In the era of commercial wrought iron, blooms were slag-riddled iron castings poured in a bloomery before being worked into wrought iron. In the era of commercial steel, blooms are intermediate-stage pieces of steel produced by a first pass of rolling (in a blooming mill) that works the ingots down to a smaller cross-sectional area, but still greater than . Blooms are usually further processed via rotary piercing, structural shape rolling and profile rolling. Common final products include structural shapes, rails, rods, and seamless pipes. Billet A billet i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sycee
A sycee (;.. from Cantonese , , ). or yuanbao () was a type of gold and silver ingot currency used in imperial China from its founding under the Qin dynasty until the fall of the Qing in the 20th century. Sycee were not made by a central bank or mint but by individual goldsmiths or silversmiths for local exchange; consequently, the shape and amount of extra detail on each ingot were highly variable. Square and oval shapes were common, but boat, flower, tortoise and others are known. Their value—like the value of the various silver coins and little pieces of silver in circulation at the end of the Qing dynasty—was determined by experienced moneyhandlers, who estimated the appropriate discount based on the purity of the silver and evaluated the weight in taels and the progressive decimal subdivisions of the tael ( mace, candareen, and cash). In present-day China, gold sycees remain a symbol of wealth and prosperity and are commonly depicted during the Chinese New Ye ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gold Bar
A gold bar, also called gold bullion or gold ingot, is a quantity of refined metallic gold of any shape that is made by a bar producer meeting standard conditions of manufacture, labeling, and record keeping. Larger gold bars that are produced by pouring the molten metal into molds are called ingots. Smaller bars may be manufactured by minting or stamping from appropriately rolled gold sheets. The standard gold bar held as gold reserves by central banks and traded among bullion dealers is the Good Delivery gold bar. The kilobar, which is in mass, and a 100 troy ounce gold bar are the bars that are more manageable and are used extensively for trading and investment. The premium on these bars when traded is very low over the spot value of the gold, making it ideal for small transfers between banks and traders. Most kilobars are flat, although some investors, particularly in Europe, prefer the brick shape. Types Based upon how they are manufactured, gold bars are categorized as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Cell
A solar cell, or photovoltaic cell, is an electronic device that converts the energy of light directly into electricity by the photovoltaic effect, which is a physical and chemical phenomenon.Solar Cells chemistryexplained.com It is a form of photoelectric cell, defined as a device whose electrical characteristics, such as , , or resistance, vary when exposed to light. Individual solar cell devices are often the electrica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Direct Chill Casting
Direct Chill casting is a method for the fabrication of cylindrical or rectangular solid ingots from non-ferrous metals, especially Aluminum, Copper, Magnesium and their alloys. The original ingots are usually further processed by other methods (rolling, forging Forging is a manufacturing process involving the shaping of metal using localized compressive forces. The blows are delivered with a hammer (often a power hammer) or a die. Forging is often classified according to the temperature at whi ..., etc.). More than half of global aluminum production uses the Direct Chill casting process.Dr. Dmitri Kopeliovich, Direct Chill (DC) casting, http://www.substech.com/dokuwiki/doku.php?id=direct_chill_dc_casting Direct Chill casting operates by pouring liquid metal continuously into a short mold (7.5–15 cm deep) that is open at the bottom. Only an outer layer of metal solidifies within the water-cooled mold. After leaving the closed mold at its bottom (e.g. with 5–15& ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wafer (electronics)
In electronics, a wafer (also called a slice or substrate) is a thin slice of semiconductor, such as a crystalline silicon (c-Si), used for the fabrication of integrated circuits and, in photovoltaics, to manufacture solar cells. The wafer serves as the substrate for microelectronic devices built in and upon the wafer. It undergoes many microfabrication processes, such as doping, ion implantation, etching, thin-film deposition of various materials, and photolithographic patterning. Finally, the individual microcircuits are separated by wafer dicing and packaged as an integrated circuit. History In the semiconductor or silicon wafer industry, the term wafer appeared in the 1950s to describe a thin round slice of semiconductor material, typically germanium or silicon. Round shape comes from single-crystal ingots usually produced using the Czochralski method. Silicon wafers were first introduced in the 1940s. By 1960, silicon wafers were being manufactured in the U.S. by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boule (crystal)
A boule is a single-crystal ingot produced by synthetic means. A boule of silicon is the starting material for most of the integrated circuits used today. In the semiconductor industry synthetic boules can be made by a number of methods, such as the Bridgman technique and the Czochralski process, which result in a cylindrical rod of material. In the Czochralski process a seed crystal is required to create a larger crystal, or ingot. This seed crystal is dipped into the pure molten silicon and slowly extracted. The molten silicon grows on the seed crystal in a crystalline fashion. As the seed is extracted the silicon solidifies and eventually a large, cylindrical boule is produced. A semiconductor crystal boule is normally cut into circular wafers using an inside hole diamond saw or diamond wire saw, and each wafer is lapped and polished to provide substrates suitable for the fabrication of semiconductor devices on its surface. The process is also used to create sapphires, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Precious Metal
Precious metals are rare, naturally occurring metallic chemical elements of high economic value. Chemically, the precious metals tend to be less reactive than most elements (see noble metal). They are usually ductile and have a high lustre. Historically, precious metals were important as currency but are now regarded mainly as investment and industrial raw materials. Gold, silver, platinum, and palladium each have an ISO 4217 currency code. The best known precious metals are the coinage metals, which are gold and silver. Although both have industrial uses, they are better known for their uses in art, jewelry, and coinage. Other precious metals include the platinum group metals: ruthenium, rhodium, palladium, osmium, iridium, and platinum, of which platinum is the most widely traded. The demand for precious metals is driven not only by their practical use but also by their role as investments and a store of value. Historically, precious metals have commanded much higher pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dendrite (metal)
A dendrite in metallurgy is a characteristic tree-like structure of crystals growing as molten metal solidifies, the shape produced by faster growth along energetically favourable crystallographic directions. This dendritic growth has large consequences in regard to material properties. Dendrites form in unary (one-component) systems as well as multi-component systems. The requirement is that the liquid (the molten material) be undercooled, aka supercooled, below the freezing point of the solid. Initially, a spherical solid nucleus grows in the undercooled melt. As the sphere grows, the spherical morphology becomes unstable and its shape becomes perturbed. The solid shape begins to express the preferred growth directions of the crystal. This growth direction may be due to anisotropy in the surface energy of the solid–liquid interface, or to the ease of attachment of atoms to the interface on different crystallographic planes, or both (for an example of the latter, see hopp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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