摘要:
A rotating refrigerator connection is provided which allows field interruption of the heat conduction path between a one, two or three stage cryogenic refrigerator and a cryostat in the event of a refrigerator failure or scheduled service.
摘要:
A thin electrical insulating coating and method for application is provided for a copper surface. The electrical insulating coating includes a bond coat layer of titanium, nickel, or NiCrAlY forming a metallurgical bond with the copper surface and an insulating layer of alumina or tantala applied to the bond coat layer. An insulating layer does not firmly adhere to copper under harsh environmental conditions such as an electroslag refining process when applied directly to the copper. However, when bond coat layer is applied between the copper and the insulating layer, it forms a strong bond adhering bond for the harsh environment.
摘要:
An apparatus and method for atomizing liquid metal are disclosed. A liquid metal supply is coupled to a nozzle for atomizing a stream of liquid metal in an atomizing zone extending from the nozzle. A viewing instrument provides a field of view extending to the atomization zone. A sensor coupled with the viewing instrument generates an image of the atomizing zone, and a control adjusts a flow rate of the stream responsive to the image.
摘要:
An apparatus for viewing the atomization of liquid metal is disclosed. A nozzle for atomizing liquid metal having a cylindrical plenum, and a melt guide tube extending axially therethrough to a melt exit orifice. The plenum defines an inner chamber coupled with an atomizing gas orifice spaced from the exit orifice and configured to provide an annular jet of atomizing gas converging in an atomizing zone extending below the exit orifice The plenum having an inner sidewall and an outer sidewall defining the inner chamber therebetween. The inner sidewall extends below the exit orifice so that the inner sidewall is spaced from the atomizing zone. A cylindrical sleeve extends through the outer sidewall to a first end in the inner chamber. A camera mounted in the sleeve has a field of view extending from the first end. A transparent window is mounted to seal the first end. The sleeve is positioned so the field of view extends through the atomization zone. A porthole extends through the inner sidewall along the field of view to provide a view of the atomization zone to the camera, and for a gas flow therefrom.
摘要:
A method for casting metal or metal alloy includes applying molten metal to a cool, rapidly moving, thermally conductive substrate so that the molten metal is rapidly cooled, and cooling the substrate by boiling a stagnant, with respect to the substrate, pool of coolant on a non-casting surface of the substrate.
摘要:
The introduction of spray formed metals into critical applications in the aircraft engine and power generation industries has been hampered by the possibility of erosion of oxide particles from a crucible lining or pouring nozzle in conventional spray forming equipment. These oxide particles may become inclusions that limit low-cycle fatigue life of parts. Use of a cold-walled induction guide (CIG) with an electrical insulation layer between copper CIG elements and the liquid metal offers a means of delivering ceramic-free alloys to a spray system with improved efficiency. CIG design options facilitated by a new oven-brazed fabrication technique resolve induction coil environmental isolation issues, correct thermal strain tolerance problems, facilitate dual frequency induction designs, allow improved electrical coupling efficiency and thermal efficiency, result in improved melt flow initiation, and facilitate disassembly without damage from the solidified melt.
摘要:
Close-coupled atomization systems and methods employing axisymmetric fluid flow and non-axisymmetric melt guide tube exit orifice configuration have demonstrated superior efficiency in the production of fine superalloy powder, such as, for example, nickel base superalloys compared to conventional close-coupled atomization utilizing an axisymmetric annular gas orifice and an axisymmetric guide melt guide tube exit orifice configuration.
摘要:
A radiation shield assembly is provided for a cryostat having a helium vessel and which includes a penetration for cooling the helium vessel. The radiation shield assembly comprises a shield having means for conducting heat toward the cryostat penetration, means for providing an isothermal surface and means for reflecting radiation. The shield surrounds the helium vessel, and is spaced away from the helium vessel by spacer means comprising isolated packets of powder insulation in permeable packages.
摘要:
An axial disconnect is provided for use with refrigerator systems in which the valve motor and displacer drive are not on the same axis as the displacer (cold end) or for situations where the stresses transmitted to the plug shields are to be minimized. The axial refrigeration connection allows field interruption of the refrigerator-cryostat conduction path to prevent excessive heat leak to the cryostat in the event of a refrigerator failure or scheduled service.
摘要:
An apparatus for generating fine liquid metal droplets from a liquid or molten metal comprises a rotatable member situated in a pressurized or evacuated chamber. Means are provided for generating an electric field at the edge of the member having sufficient strength to overcome the surface tension of the metal. A liquid metal delivery means directs liquid metal onto a surface of the member over which the metal flows toward the edge as the member is spun. As the liquid metal leaves the surface at the edge, the force of the electric field causes fine liquid metal droplets which are more uniform and smaller than those produced without an electric field to form. A method for forming fine liquid metal droplets is also disclosed.