摘要:
Disclosed herein is method for making a wire comprising contacting a first end of a first superconducting wire with a second end of a second superconducting wire, wherein the superconducting wire comprises a superconducting filament having a superconducting composition comprising magnesium diboride; heating the first end of the first superconducting wire with the second end of the second superconducting wire at a point to form a joint, wherein the superconducting filament having the superconducting composition is in continuous electrical contact with any other part of the superconducting filament after the formation of the joint.
摘要:
A Magnetic Resonance Imaging (MRI) system having a vacuum vessel positioned about an imaging volume, one or more high temperature superconducting coils positioned within the vacuum vessel, and a cryocooler coupled to the vacuum vessel to operate the superconducting coil at a temperature above 10 K. At least one gradient coil is positioned between an imaging volume and the superconducting coil without any thermal shielding interposed between the gradient coil and the superconducting coil.
摘要:
A multi-filament superconducting wire in which the filaments comprise zirconia-stabilized ultra-fine grain Nb3Sn. The superconducting wire is formed by wire-drawing a preform comprising a metallic matrix and at least one niobium alloy rod having zirconium and oxygen in solid solution and heat treating the drawn wire in the presence of tin to yield at least one continuous filament comprising ultra-fine grain Nb3Sn having semi-coherent ZrO2 precipitates disposed therein. The ZrO2 precipitates serve to stabilize the ultra-fine grain microstructure of the Nb3Sn at temperatures up to 1100° C. and allows Nb3Sn to maintain the ultra-fine grain microstructure when heat treated at temperatures that are greater than those previously used. By using higher temperatures to form Nb3Sn, the time required for heat treatment can be significantly reduced.
摘要:
A method for thermal forming includes determining a process window for initiating cooling, locally heating at least one region on a specimen to achieve a pre-selected geometry deformation, initiating active cooling of the heated region within the process window to control at least one material property of the specimen at the heated region and actively cooling the heated region to a pre-selected temperature. A system for thermal forming includes a thermal source for heating the region on the specimen to achieve a pre-selected geometry deformation, an active cooling module for cooling the region to a pre-selected temperature and a control module to control at least one of the thermal source and active cooling module in accordance with a process window to initiate active cooling to control at least one material property of the specimen at the heated region. The process window has an upper time limit for initiating cooling.
摘要:
A nanocomposite comprising a plurality of nanoparticles dispersed in a molybdenum-based matrix, and an x-ray tube component formed from such a nanocomposite. The nanocomposite contains volume fraction of nanoparticle dispersoids in a range from about 2 volume percent to about 20 volume percent. A method of making such molybdenum-based nanocomposites is also disclosed.
摘要:
A method of making nano/sub-micron sized grains in a work piece material having a lateral side has the steps of providing a die. The die has an entrance channel with a longitudinal axis and an exit channel. The entrance channel and the exit channel are connected to one another to form an angle. The method has the step of providing a first sacrificial material with a complementary size to the work piece and placing the sacrificial first material and the work piece in an entrance channel. The first sacrificial material and the work piece are aligned with the longitudinal axis. The method has the step of extruding the combination of the first sacrificial material, and the work piece through the intersection of the entrance and the exit channels. The resulting shear deformation forms the nano/sub-micron sized grains in the work piece. This configuration reduces frictional effects thereby producing homogenous nano grain structure. This configuration reduces applied load and enables equal channel angular extrusion of thin sheets.
摘要:
A method of manufacturing a magnetic resonance imaging (MRI) device is provided including providing at least one magnet positioned between a keeper device and a yoke, the keeper device being positioned at a pole region of the at least one magnet, positioning at least one pole device at the pole region of the at least one magnet, and removing the keeper device from the pole region to allow the at least one pole device to be positioned at the pole region of the at least one magnet.
摘要:
Electric machines can be improved or uprated to reduce core-end losses using lower core loss material such as high grade iron silicon. A machine uprating entails removing at least a last one of the stacked lamination packages at each end of the stator core, and re-stacking the removed lamination packages with the lower core loss material.
摘要:
A method for fabricating a component includes providing a workpiece, an electroerosion apparatus comprising an electrode tool. The electroerosion apparatus is operated on the workpiece, for removing a portion thereof. A method for fabricating a composite magnet includes a workpiece comprising a composite material including a magnetizable material and an epoxy resin. An electroerosion apparatus, comprising an electrode tool having an abrasive material, removes a portion of the workpiece by an abrasive action of the electrode tool on the workpiece.
摘要:
A nanocomposite comprising a plurality of nanoparticles dispersed in a metallic alloy matrix, and a structural component formed from such a nanocomposite. The metallic matrix comprises at least one of a nickel-based alloy and an iron-based alloy. The nanocomposite contains a higher volume fraction of nanoparticle dispersoids than those presently available. The structural component include those used in hot gas path assemblies, such as steam turbines, gas turbines, and aircraft turbine. A method of making such nanocomposites is also disclosed.