|
Hexoloy
Hexoloy is a registered trademark for a pressureless sintered form of alpha silicon carbide. Hexoloy SA is made by sintering silicon carbide powder. This process bonds the powder together to create a self-bonded product which is extremely hard and lightweight. It has a high resistance to corrosion, erosion, high temperature and thermal shock. It is ideal for applications involving liquid and hot gas exposure, mechanical seal faces, mineral and chemical processing kilns and furnaces. Even with use at high temperatures Hexoloy maintains high strength and stability. Hexoloy has high thermal conductivity, equal to that of stainless steel and 5 times that of alumina and excellent wear resistance – 50% harder than tungsten carbide. History Sintered silicon carbide was patented by the Pittsburgh-based Carborundum Corporation in 1979 under U.S. patent 4,179,299. It is currently held by Saint-Gobain. It was registered and trademarked as Hexoloy in 1984. The first large commercial use for H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermal Conductivity
The thermal conductivity of a material is a measure of its ability to conduct heat. It is commonly denoted by k, \lambda, or \kappa. Heat transfer occurs at a lower rate in materials of low thermal conductivity than in materials of high thermal conductivity. For instance, metals typically have high thermal conductivity and are very efficient at conducting heat, while the opposite is true for insulating materials like Rockwool or Styrofoam. Correspondingly, materials of high thermal conductivity are widely used in heat sink applications, and materials of low thermal conductivity are used as thermal insulation. The reciprocal of thermal conductivity is called thermal resistivity. The defining equation for thermal conductivity is \mathbf = - k \nabla T, where \mathbf is the heat flux, k is the thermal conductivity, and \nabla T is the temperature gradient. This is known as Fourier's Law for heat conduction. Although commonly expressed as a scalar, the most general form of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pittsburgh
Pittsburgh ( ) is a city in the Commonwealth (U.S. state), Commonwealth of Pennsylvania, United States, and the county seat of Allegheny County, Pennsylvania, Allegheny County. It is the most populous city in both Allegheny County and Western Pennsylvania, the List of municipalities in Pennsylvania#Municipalities, second-most populous city in Pennsylvania behind Philadelphia, and the List of United States cities by population, 68th-largest city in the U.S. with a population of 302,971 as of the 2020 United States census, 2020 census. The city anchors the Pittsburgh metropolitan area of Western Pennsylvania; its population of 2.37 million is the largest in both the Ohio Valley and Appalachia, the Pennsylvania metropolitan areas, second-largest in Pennsylvania, and the List of metropolitan statistical areas, 27th-largest in the U.S. It is the principal city of the greater Pittsburgh–New Castle–Weirton combined statistical area that extends into Ohio and West Virginia. Pitts ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saint-Gobain
Compagnie de Saint-Gobain S.A. () is a French multinational corporation, founded in 1665 in Paris and headquartered on the outskirts of Paris, at La Défense and in Courbevoie. Originally a mirror manufacturer, it now also produces a variety of construction, high-performance, and other materials. History 1665-1789: Manufacture royale Since the middle of the 17th century, luxury products such as silk textiles, lace and mirrors were in high demand. In the 1660s, mirrors had become very popular among the upper classes of society: Italian cabinets, châteaux and ornate side tables and pier-tables were decorated with this expensive and luxurious product. At the time, however, the French were not known for mirror technology; instead, the Republic of Venice was known as the world leader in glass manufacturing, controlling a technical and commercial monopoly of the glass and mirror business. French minister of finance Olivier Bluche wanted France to become completely self-sufficien ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
US Patent Office
The United States Patent and Trademark Office (USPTO) is an agency in the U.S. Department of Commerce that serves as the national patent office and trademark registration authority for the United States. The USPTO's headquarters are in Alexandria, Virginia Alexandria is an independent city in the northern region of the Commonwealth of Virginia, United States. It lies on the western bank of the Potomac River approximately south of downtown Washington, D.C. In 2020, the population was 159,467. ..., after a 2005 move from the Crystal City area of neighboring Arlington County, Virginia, Arlington, Virginia. The USPTO is "unique among federal agencies because it operates solely on fees collected by its users, and not on taxpayer dollars". Its "operating structure is like a business in that it receives requests for services—applications for patents and trademark registrations—and charges fees projected to cover the cost of performing the services [it] provide[s]". T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silicon Carbide
Silicon carbide (SiC), also known as carborundum (), is a hard chemical compound containing silicon and carbon. A semiconductor, it occurs in nature as the extremely rare mineral moissanite, but has been mass-produced as a powder and crystal since 1893 for use as an abrasive. Grains of silicon carbide can be bonded together by sintering to form very hard ceramics that are widely used in applications requiring high endurance, such as car brakes, car clutches and ceramic plates in bulletproof vests. Large single crystals of silicon carbide can be grown by the Lely method and they can be cut into gems known as synthetic moissanite. Electronic applications of silicon carbide such as light-emitting diodes (LEDs) and detectors in early radios were first demonstrated around 1907. SiC is used in semiconductor electronics devices that operate at high temperatures or high voltages, or both. Natural occurrence Naturally occurring moissanite is found in only minute quantities in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbides
In chemistry, a carbide usually describes a compound composed of carbon and a metal. In metallurgy, carbiding or carburizing is the process for producing carbide coatings on a metal piece. Interstitial / Metallic carbides The carbides of the group 4, 5 and 6 transition metals (with the exception of chromium) are often described as interstitial compounds. These carbides have metallic properties and are refractory. Some exhibit a range of stoichiometries, being a non-stoichiometric mixture of various carbides arising due to crystal defects. Some of them, including titanium carbide and tungsten carbide, are important industrially and are used to coat metals in cutting tools. The long-held view is that the carbon atoms fit into octahedral interstices in a close-packed metal lattice when the metal atom radius is greater than approximately 135 pm: *When the metal atoms are cubic close-packed, (ccp), then filling all of the octahedral interstices with carbon achieves 1:1 stoi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
