Element History - Brief Review Private8 months ago - عقارات للاجار - مكة - 54 views
Tungsten is a heavy metallic element, a member of the third series of transition metals. It has the symbol W, its atomic number is 74, and its atomic weight is 183.85. The name is derived from the Swedish tung sten, meaning “heavy stone.” Tungsten is also known as wolfram, from WOLFRAMITE, the mineral from which the element was first recognized by the English chemist Peter Woulfe in 1779. The metal was first isolated in 1783 by Spanish scientists Jose and Fausto d’ElhuyaTungsten plate sheet is isostatically pressed and sintered from our high purity tungsten powders to compact ingots by powder metallurgy. Following the powder metallurgy is a series of further deformations and heat treatments until the required products are finished. We are now capable of machining tungsten plate and sheet with a range of thickness from 3.15 inches (80 mm) to less than 0.004 inches (0.1 mm).
CHEMETAL USA is a recognized manufacturer and supplier of high quality tungsten plate and tungsten sheet. Every tungsten plate we supply is under stringent quality control at every stage of production, including the rolling, annealing, surface treatment and a series of tests. Thanks to our experience and capacity in the field of milling tungsten product, we can always guarantee that our customers receive high-performance tungsten plate products with exceptional purity, roughness, dimension, flatness and surface condition.
Zirconium is abundant in S-type stars in which heavier elements are formed by neutron capture. Traces of the element are also present in the Sun, and rock brought back from the moon was found to have a surprisingly high zirconium content.
r through the reduction, by means of charcoal, of the tungstic acid found in wolframite.
Hafnium is dispersed in Earth’s crust to the extent of three parts per million and is invariably found in zirconium minerals up to a few percent compared with zirconium. For example, the minerals zircon, ZrSiO4 (zirconium orthosilicate), and baddeleyite, which is essentially pure zirconium dioxide, ZrO2, generally have a hafnium content that varies from a few tenths of 1 percent to several percent. Altered zircons, like some alvites and cyrtolites, products of residual crystallization, show greater percentages of hafnium (up to 17 percent hafnium oxide in cyrtolite from Rockport, Mass., U.S.). Commercial sources of hafnium-bearing zirconium minerals are found in beach sands and river gravel in the United States (principally Florida), Australia, Brazil, western Africa, and India. Hafnium vapour has been identified in the Sun’s atmosphere.
Why Can Molybdenum Wire Cut Metal?
Many people have heard of wire cutting, and the molybdenum wire cutting is also a kind of wire cutting. Then why can molybdenum wire cut metal? Many people may think that molybdenum wire cutting is to cut metal with a molybdenum wire, just like sawing wood with a saw. In fact, this is not the case. So in this article, we’ll try to find out the reason why molybdenum wire can cut metal. But first of all, let’s figure out what are molybdenum and molybdenum wire.
Molybdenum wire is a kind of metal wire made of molybdenum as the main component (above 99%) with a diameter between 0.02 mm and 0.2 mm. It has a tough texture and high tensile strength, mainly used for cutting workpieces in the industry. Molybdenum wires have high precision, low wire breaking rate, and fast processing speed, which can realize stable long time continuous processing. Molybdenum wires can not only process various metals, but also are widely used for lead wire, heating element, and so on.
NITINOL WIRE DESCRIPTION
Nitinol wire is a nickel-titanium alloy with super elasticity and shape memory properties. Shape memory refers to the ability of Nitinol to undergo deformation at one temperature, then recover its original, under formed shape upon heating above its transformation temperature. Super elasticity occurs at a narrow temperature range just above its transformation temperature; in this case, no heating is necessary to cause the under formed shape to recover, and the material exhibits enormous elasticity, some 10-30 times that of ordinary metal.
Niobium is a tough, shiny, silver-gray, soft, ductile metal that somewhat resembles stainless steel in appearance. Niobium is relatively low in density, yet can maintain its strength at high temperatures. It has excellent corrosion resistance to liquid metals, and can be easily fabricated into wrought products.
Commercial niobium alloy is relatively low in strength and extremely ductile, and can be cold-worked over 70% before annealing becomes necessary. The resulting ease of fabrication into complex parts combined with relatively low density frequently favors the selection of niobium alloys over other refractory metals such as molybdenum, tantalum, or tungsten.