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Brass
Brass is an alloy of copper and zinc, in proportions which can be varied to achieve different colours and mechanical, electrical, acoustic and chemical properties, but copper typically has the larger proportion, generally copper and zinc. In use since prehistoric times, it is a substitutional alloy: atoms of the two constituents may replace each other within the same crystal structure. Brass is similar to bronze, a copper alloy that contains tin instead of zinc. Both bronze and brass may include small proportions of a range of other Chemical element, elements including arsenic, lead, phosphorus, aluminium, manganese and silicon. Historically, the distinction between the two alloys has been less consistent and clear, and increasingly museums use the more general term "list of copper alloys, copper alloy". Brass has long been a popular material for its bright gold-like appearance and is still used for drawer pulls and door handle, doorknobs. It has also been widely used to ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Copper Alloys
Copper alloys are metal Alloy, alloys that have copper as their principal component. They have high resistance against corrosion. Of the large number of different types, the best known traditional types are bronze, where tin is a significant addition, and brass, using zinc instead. Both of these are imprecise terms. Latten is a further term, mostly used for coins with a very high copper content. Today the term ''copper alloy'' tends to be substituted for all of these, especially by museums. Copper deposits are abundant in most parts of the world (globally 70 parts per million), and it has therefore always been a relatively cheap metal. By contrast, tin is relatively rare (2 parts per million), and in Europe and the Mediterranean region, and even in prehistoric times had to be Tin sources and trade during antiquity, traded considerable distances, and was expensive, sometimes virtually unobtainable. Zinc is even more common at 75 parts per million, but is harder to extract from its ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zinc
Zinc is a chemical element; it has symbol Zn and atomic number 30. It is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodic table. In some respects, zinc is chemically similar to magnesium: both elements exhibit only one normal oxidation state (+2), and the Zn2+ and Mg2+ ions are of similar size. Zinc is the 24th most abundant element in Earth's crust and has five stable isotopes. The most common zinc ore is sphalerite (zinc blende), a zinc sulfide mineral. The largest workable lodes are in Australia, Asia, and the United States. Zinc is refined by froth flotation of the ore, roasting, and final extraction using electricity ( electrowinning). Zinc is an essential trace element for humans, animals, plants and for microorganisms and is necessary for prenatal and postnatal development. It is the second most abundant trace metal in humans after iron, an import ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrical Conductivity
Electrical resistivity (also called volume resistivity or specific electrical resistance) is a fundamental specific property of a material that measures its electrical resistance or how strongly it resists electric current. A low resistivity indicates a material that readily allows electric current. Resistivity is commonly represented by the Greek alphabet, Greek letter (Rho (letter), rho). The SI unit of electrical resistivity is the ohm-metre (Ω⋅m). For example, if a solid cube of material has sheet contacts on two opposite faces, and the Electrical resistance, resistance between these contacts is , then the resistivity of the material is . Electrical conductivity (or specific conductance) is the reciprocal of electrical resistivity. It represents a material's ability to conduct electric current. It is commonly signified by the Greek letter (Sigma (letter), sigma), but (kappa) (especially in electrical engineering) and (gamma) are sometimes used. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bronze
Bronze is an alloy consisting primarily of copper, commonly with about 12–12.5% tin and often with the addition of other metals (including aluminium, manganese, nickel, or zinc) and sometimes non-metals (such as phosphorus) or metalloids (such as arsenic or silicon). These additions produce a range of alloys some of which are harder than copper alone or have other useful properties, such as strength, ductility, or machinability. The archaeological period during which bronze was the hardest metal in widespread use is known as the Bronze Age. The beginning of the Bronze Age in western Eurasia is conventionally dated to the mid-4th millennium BCE (~3500 BCE), and to the early 2nd millennium BCE in China; elsewhere it gradually spread across regions. The Bronze Age was followed by the Iron Age, which started about 1300 BCE and reaching most of Eurasia by about 500 BCE, although bronze continued to be much more widely used than it is in modern times. Because historica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hose Coupling
A hose coupling is a connector on the end of a hose to connect (or ''couple'') it with another hose or with a tap or a hose appliance, such as an irrigation sprinkler. It is usually made of steel, brass, stainless steel, aluminium or plastic. Due to the great variety of the designs and the number of countries in which they were created, it is difficult to trace the origin of many. Patents that cover designs similar to those below include: * 1876: Hose-coupling, No. 175,232. * Coupling for hose and pipe. US 894900 A * 1915: Coupling. US 1248558 A * 1931: Coupling. US 1947593 A (claw-types) Threaded coupler types Garden hose thread See Garden hose thread. See also Hoselink and Hozelock plastic click-on connectors. GFR NF E 29-579 GFR Ground joint A "boss" ground joint coupling valve hose coupling, primarily used for compressed air or steam. It consists of a stem, wing nut and spud. It seals as a soft copper seat located in the spud is drawn against the stem by ti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Copper
Copper is a chemical element; it has symbol Cu (from Latin ) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orange color. Copper is used as a conductor of heat and electricity, as a building material, and as a constituent of various metal alloys, such as sterling silver used in jewelry, cupronickel used to make marine hardware and coins, and constantan used in strain gauges and thermocouples for temperature measurement. Copper is one of the few metals that can occur in nature in a directly usable, unalloyed metallic form. This means that copper is a native metal. This led to very early human use in several regions, from . Thousands of years later, it was the first metal to be smelted from sulfide ores, ; the first metal to be cast into a shape in a mold, ; and the first metal to be purposely alloyed with another metal, tin, to create bronze, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Door Handle
A door handle or doorknob is a handle used to open or close a door. Door handles can be found on all types of doors including: exterior doors of residential building, residential and commercial buildings, internal doors, cupboard doors and vehicle doors. There are many designs of door handle, depending on the appropriate use. A large number of handles, particularly for commercial and residential doors, incorporate latching or locking mechanisms or are manufactured to fit to standardised door locking or latching mechanisms. The most common types of door handle are the lever handle and the doorknob. Door handles can be made out of a plethora of materials. Examples include brass, porcelain, cut glass, wood, and bronze. Door handles have been in existence for at least 5000 years, and its design has evolved since, with more advanced mechanism, types, and designs made. Some door handles are also arm- or foot-operated to reduce transmission of contagious illnesses. Types *The most ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benin Bronzes
The Benin Bronzes are a group of several thousand metal plaques and sculptures that decorated the royal palace of the Kingdom of Benin, in what is now Edo State, Nigeria. The metal plaques were produced by the Guild of Benin Bronze Casters, now located in Igun Street, also known as Igun-Eronmwon Quarters. Collectively, the objects form the best examples of Benin art and were created from the fourteenth century by artists of the Edo people. The plaques, which in the Edo language are called ''Ama'', depict scenes or represent themes in the history of the kingdom. Apart from the plaques, other sculptures in brass or bronze include portrait heads, jewellery, and smaller pieces. Some of the dramatic sculptures date to the fourteenth century, but the bulk of the collection dates to the fifteenth and sixteenth centuries. It is believed that two "Golden Ages" in Benin metal workmanship occurred during the reigns of Esigie ( 1550) and of Eresoyen (1735–1750), when their workmanship ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Friction
Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. Types of friction include dry, fluid, lubricated, skin, and internal -- an incomplete list. The study of the processes involved is called tribology, and has a history of more than 2000 years. Friction can have dramatic consequences, as illustrated by the use of friction created by rubbing pieces of wood together to start a fire. Another important consequence of many types of friction can be wear, which may lead to performance degradation or damage to components. It is known that frictional energy losses account for about 20% of the total energy expenditure of the world. As briefly discussed later, there are many different contributors to the retarding force in friction, ranging from asperity deformation to the generation of charges and changes in local structure. When two bodies in contact move relative to each other, due to these variou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aluminium
Aluminium (or aluminum in North American English) is a chemical element; it has chemical symbol, symbol Al and atomic number 13. It has a density lower than that of other common metals, about one-third that of steel. Aluminium has a great affinity towards oxygen, passivation (chemistry), forming a protective layer of aluminium oxide, oxide on the surface when exposed to air. It visually resembles silver, both in its color and in its great ability to reflect light. It is soft, magnetism, nonmagnetic, and ductility, ductile. It has one stable isotope, 27Al, which is highly abundant, making aluminium the abundance of the chemical elements, 12th-most abundant element in the universe. The radioactive decay, radioactivity of aluminium-26, 26Al leads to it being used in radiometric dating. Chemically, aluminium is a post-transition metal in the boron group; as is common for the group, aluminium forms compounds primarily in the +3 oxidation state. The aluminium cation Al3+ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drawer Pull
A drawer pull (wire pull or simply pull) is a handle to pull a drawer out of a chest of drawers, cabinet or other furniture piece. A drawer pull often includes an escutcheon plate to (or through) which the handle is fastened. The handle may swing from one or two mounts ("drop handle" or "swing handle"), a form of bail handle, making a drop drawer pull. The handle may also be permanently fastened to the plate. The plate may be ornamented by piercing, embossing, or engraving Engraving is the practice of incising a design on a hard, usually flat surface by cutting grooves into it with a Burin (engraving), burin. The result may be a decorated object in itself, as when silver, gold, steel, or Glass engraving, glass ar ..., and may receive decorative finishes such as plating, etching, and antiquing. Handle stock may be round, rectangular, or irregular forged shapes. Thomas Francis Googerty (1911) ''Hand-forging and Wrought-iron Ornamental Work'', Popular Mechanics Company ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
