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Bismanol
Bismanol is a magnetic alloy of bismuth and manganese (manganese bismuthide) developed by the US Naval Ordnance Laboratory. History Bismanol, a permanent magnet made from powder metallurgy of manganese bismuthide, was developed by the US Naval Ordnance Laboratory in the early 1950s – at the time of invention it was one of the highest coercive force permanent magnets available, at 3000 oersteds. Coercive force reached 3650 oersteds and magnetic flux density 4800 by the mid 1950s. The material was generally strong, and stable to shock and vibration, but had a tendency to chip. Slow corrosion of the material occurred under normal conditions. The material was used to make permanent magnet A magnet is a material or object that produces a magnetic field. This magnetic field is invisible but is responsible for the most notable property of a magnet: a force that pulls on other ferromagnetic materials, such as iron, steel, nickel, c ...s for use in small electric motors. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
US Naval Ordnance Laboratory
The Naval Ordnance Laboratory (NOL) was a facility in the White Oak area of Montgomery County, Maryland. The location is now used as the headquarters of the U.S. Food and Drug Administration. Origins The U.S. Navy Mine Unit, later the Mine Laboratory at the Washington, D.C., Navy Yard, was established in 1918, and the first Officer in Charge (OIC) arrived in February 1919, marking the beginning of the Laboratory. In 1929 the Mine Laboratory was merged with the Experimental Ammunition Station in Indian Head to form the Naval Ordnance Laboratory. NOL began slowly, and it was not until the beginnings of World War II, when Germany's aircraft-laid magnetic mine began to cause serious problems for the Allies. As the importance of NOL's work became apparent, it also became apparent that there wasn't enough space at the Navy Yard to accommodate the necessary research facilities. In 1944, acquisition, planning and construction work began at a wooded site located at 10903 New Hampshir ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ferromagnetic Materials
Ferromagnetism is a property of certain materials (such as iron) that results in a significant, observable magnetic permeability, and in many cases, a significant magnetic coercivity, allowing the material to form a permanent magnet. Ferromagnetic materials are noticeably attracted to a magnet, which is a consequence of their substantial magnetic permeability. Magnetic permeability describes the induced magnetization of a material due to the presence of an external magnetic field. For example, this temporary magnetization inside a steel plate accounts for the plate's attraction to a magnet. Whether or not that steel plate then acquires permanent magnetization depends on both the strength of the applied field and on the coercivity of that particular piece of steel (which varies with the steel's chemical composition and any heat treatment it may have undergone). In physics, multiple types of material magnetism have been distinguished. Ferromagnetism (along with the similar eff ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetic Alloy
A magnetic alloy is a combination of various metals from the periodic table such as ferrite that exhibits magnetic properties such as ferromagnetism. Typically the alloy contains one of the three main magnetic elements (which appear on the Bethe-Slater curve): iron (Fe), nickel (Ni), or cobalt (Co). However, alloys such as Heusler alloys exhibit ferromagnetic properties without any of the preceding 3 elements, and alloys of iron and manganese such as stainless steels may be essentially nonmagnetic at room temperature. Magnetic properties of an alloy are highly dependent not only on the composition but also on heat treatment and mechanical processing. Magnetic alloys have become common, especially in the form of steel (iron and carbon), alnico (iron, nickel, cobalt, and aluminum), and permalloy (iron and nickel). So-called "neodymium magnets" are alloys of neodymium, iron and boron forming the crystal structure Nd2Fe14B. After magnetization, items made out of these alloys will r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bismuth
Bismuth is a chemical element; it has symbol Bi and atomic number 83. It is a post-transition metal and one of the pnictogens, with chemical properties resembling its lighter group 15 siblings arsenic and antimony. Elemental bismuth occurs naturally, and its sulfide and oxide forms are important commercial ores. The free element is 86% as dense as lead. It is a brittle metal with a silvery-white color when freshly produced. Surface oxidation generally gives samples of the metal a somewhat rosy cast. Further oxidation under heat can give bismuth a vividly iridescent appearance due to thin-film interference. Bismuth is both the most diamagnetic element and one of the least thermally conductive metals known. Bismuth was formerly understood to be the element with the highest atomic mass whose nuclei do not spontaneously decay. However, in 2003 it was found to be very slightly radioactive. The metal's only primordial isotope, bismuth-209, undergoes alpha decay with a half-l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Manganese
Manganese is a chemical element; it has Symbol (chemistry), symbol Mn and atomic number 25. It is a hard, brittle, silvery metal, often found in minerals in combination with iron. Manganese was first isolated in the 1770s. It is a transition metal with a multifaceted array of industrial alloy uses, particularly in stainless steels. It improves strength, workability, and resistance to wear. Manganese oxide is used as an oxidising agent, as a rubber additive, and in glass making, fertilisers, and ceramics. Manganese sulfate can be used as a fungicide. Manganese is also an essential human dietary element, important in macronutrient metabolism, bone formation, and free radical defense systems. It is a critical component in dozens of proteins and enzymes. It is found mostly in the bones, but also the liver, kidneys, and brain. In the human brain, the manganese is bound to manganese metalloproteins, most notably glutamine synthetase in astrocytes. Manganese is commonly found in labo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Permanent Magnet
A magnet is a material or object that produces a magnetic field. This magnetic field is invisible but is responsible for the most notable property of a magnet: a force that pulls on other ferromagnetic materials, such as iron, steel, nickel, cobalt, etc. and attracts or repels other magnets. A permanent magnet is an object made from a material that is magnetized and creates its own persistent magnetic field. An everyday example is a refrigerator magnet used to hold notes on a refrigerator door. Materials that can be magnetized, which are also the ones that are strongly attracted to a magnet, are called Ferromagnetism, ferromagnetic (or ferrimagnetic). These include the elements iron, nickel and cobalt and their alloys, some alloys of rare-earth element, rare-earth metals, and some naturally occurring minerals such as lodestone. Although ferromagnetic (and ferrimagnetic) materials are the only ones attracted to a magnet strongly enough to be commonly considered magnetic, all oth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Powder Metallurgy
Powder metallurgy (PM) is a term covering a wide range of ways in which materials or components are made from metal powders. PM processes are sometimes used to reduce or eliminate the need for subtractive manufacturing, subtractive processes 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 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. 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 tungsten carbide. Tungsten carbide is used to cut and form other metals and is made from tungsten carbide particles bonded with cobalt. Tu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oersted
The oersted (, symbol Oe) is the coherent derived unit of the Magnetic field#The H-field, auxiliary magnetic field H in the CGS-EMU and Gaussian units, Gaussian systems of units. It is equivalent to 1 dyne per maxwell (unit), maxwell. Difference between Gaussian and SI systems In the Gaussian system, the unit of the H-field is the oersted and the unit of the B-field is the gauss (unit), gauss. In the SI, the unit ampere per metre (A/m), which is equivalent to newton (unit), newton per weber (unit), weber, is used for the H-field and the unit tesla (unit), tesla is used for the B-field. History The unit was established by the International Electrotechnical Commission, IEC in the 1930s in honour of Danish physicist Hans Christian Ørsted. Ørsted discovered the connection between magnetism and electric current when a magnetic field produced by a current-carrying copper bar deflected a magnetised needle during a lecture demonstration. Definition The oersted is defined as a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neodymium Magnet
A nickel-plated neodymium magnet on a bracket from a hard disk drive file:Nd-magnet.jpg">Nickel-plated neodymium magnet cubes Left: high-resolution transmission electron microscopy image of Nd2Fe14B; right: crystal structure with unit cell marked">crystal structure with unit cell">crystal structure">transmission electron microscopy image of Nd2Fe14B; right: crystal structure with unit cell marked A neodymium magnet (also known as NdFeB, NIB or Neo magnet) is a permanent magnet made from an alloy of neodymium, iron, and boron to form the Nd2Fe14B tetragonal crystal system, tetragonal crystalline structure. They are the most widely used type of rare-earth magnet. Developed independently in 1984 by General Motors and Sumitomo Special Metals, neodymium magnets are the strongest type of permanent magnet available commercially. They have replaced other types of magnets in many applications in modern products that require strong permanent magnets, such as electric motors in c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alnico
Alnico is a family of iron alloys which, in addition to iron are composed primarily of aluminium (Al), nickel (Ni), and cobalt (Co), hence the acronym ''al-ni-co''. They also include copper, and sometimes titanium. Alnico alloys are ferromagnetic, and are used to make permanent magnets. Before the development of rare-earth magnets in the 1970s, they were the strongest permanent magnet type. Other trade names for alloys in this family are: ''Alni, Alcomax, Hycomax, Columax'', and ''Ticonal''. The composition of alnico alloys is typically 8–12% Al, 15–26% Ni, 5–24% Co, up to 6% Cu, up to 1% Ti, and the rest is Fe. The development of alnico began in 1931, when T. Mishima in Japan discovered that an alloy of iron, nickel, and aluminum had a coercivity of , double that of the best magnet steels of the time. Properties Alnico alloys can be magnetised to produce strong magnetic fields and have a high coercivity (resistance to demagnetization), thus making strong permanent magn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetic Alloys
A magnetic alloy is a combination of various metals from the periodic table such as ferrite that exhibits magnetic properties such as ferromagnetism. Typically the alloy contains one of the three main magnetic elements (which appear on the Bethe-Slater curve): iron (Fe), nickel (Ni), or cobalt (Co). However, alloys such as Heusler alloys exhibit ferromagnetic properties without any of the preceding 3 elements, and alloys of iron and manganese such as stainless steels may be essentially nonmagnetic at room temperature. Magnetic properties of an alloy are highly dependent not only on the composition but also on heat treatment and mechanical processing. Magnetic alloys have become common, especially in the form of steel (iron and carbon), alnico (iron, nickel, cobalt, and aluminum), and permalloy (iron and nickel). So-called "neodymium magnets" are alloys of neodymium, iron and boron forming the crystal structure Nd2Fe14B. After magnetization, items made out of these alloys will r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
