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New Roles For Ceramic Parts
removes hydrogen gas from molten aluminum. A combination of freeze molding and injection molding lets Blasch Precision Ceramics, Albany, N.Y., make a permeable ceramic from a silicon carbide/alumina composite. The process generates <5-um pores in the degasser head but a stronger, denser shaft...
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Microfiber Ring Protects Bearings from Shaft Currents
Microfiber Ring Protects Bearings from Shaft Currents The ceramic coated, insulated generator bearings at the top of one wind-turbine tower failed only 11 months after the tower was brought online. The company that owns and operates the wind farm replaced the bearings and slip rings, but the new...
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Face Seals
important criterion. The primary sealing interface is between rotating and stationary members that form a plane perpendicular to the shaft. The sealing area is a narrow ring where the two faces contact. One of the sealing faces is usually metal or ceramic and the other is usually graphite or plastic...
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Scanning for Ideas: A Motor Pump Built for Solar Power
. It consists of a hemispheric rotor and impeller that sits on a hard, wear-resistant ceramic ball. There are no conventional shaft bearings or seals, which eliminates play in the bearings and the resulting noise. The ceramic ball, acting as a self-aligning bearing, is lubed and cooled by the fluid...
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Precision moves with pint-sized motors
for piezomotors is a compound of lead (Pb), zirconium (Zr), and titanium (Ti) oxide powder. The powder is fired and electrically polarized to align material domains along a primary axis. The finished material is a ceramic dubbed PZT. There are several suppliers of PZT material. They can source PZT as raw...
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Cool running
the spindle and tooling, making it difficult to hold size on machined parts. Standard spindle-bearings under these conditions may reach temperatures above 150 F, exacerbating the problem. But special hybrid ceramic tapered roller bearings meet all the above design criteria and, under the same conditions...
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Coarse and fine combined
New actuators can traverse both long distances and subnanometer increments with equal ease. Among the applications for ceramic servomotors are hard-disk certification tools (top). Here a ceramic servo moves a singleaxis stage controlling a read/write head. The motors are also widely applied...
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Hard-Coating Removal That s Easy on the Environment
what you need to know. The AWJ process works especially well on tough coatings that see extreme environments, like molybdenum- chromium-aluminum-yttrium (MCrAlY) ceramic thermal-barrier coatings (TBCs) that protect superalloys in gas turbines. Despite careful engineering of the coatings, intermediate...
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Definite and Special-Purpose Motors
be smaller. In toothless motors that use ceramic magnets, flux density in the air gap is much lower than in conventional motors. The low density results from the large air gap, an inherent characteristic of toothless construction. Toothless motors equipped with rare-earth magnets, however, operate at high...
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Thermal spray: Better performance for less
. Thermal-spray coatings of metallic, carbide, ceramic, or cermet material are said to perform as well or better than parts produced in the same materials for a significantly lower investment. Thermally coated parts are also more resilient where extreme heat, wear, or corrosion can degrade conventional...