Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: An apparatus, system and method for viewing an industrial process in an obscuring environment, such as molten metal atomization, is disclosed. An enclosure defining a chamber for containing a particulate form from atomized liquid metal has a nozzle for atomizing liquid metal mounted thereon in communication with the chamber whereby particles recirculate throughout the chamber. The nozzle being comprised of a cylindrical plenum means and a melt guide tube extending axially therethrough to an exit orifice. The plenum means is configured to provide a jet of atomizing gas converging in an atomizing zone extending from the exit orifice. A viewing means extends through the enclosure to a viewing orifice adjacent the atomization zone, the viewing means being configured to extend a field of view through the chamber to the atomization zone.

Abstract: 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.

Abstract: A refrigerator evaporator is formed in a spread serpentine configuration having a plurality of straight tube segments and a plurality of bent tube segments where each one of the straight tube segments is joined at an acute angle to at least one other straight tube segment. The straight tube segments are arranged in a number of planar rows which are adjacent and parallel to one another. Approximately 25-50 percent of the cross-sectional area of the evaporator is not occupied by tubing or any attached fins. A cross flow blower disposed at one end of the evaporator draws air longitudinally over the evaporator.

Abstract: A nozzle for atomizing molten metal to provide a powder having improved yield of fine particles is disclosed. The nozzle is comprised of a gas plenum, a melt delivery tube, and an annular inner wall means within the gas plenum for delivering atomizing gas to the exit orifice of the melt delivery tube. The exit orifice of the melt delivery tube has a ratio of inside diameter to outside diameter that provides a reduced flow of liquid through the tube during atomization.

Abstract: 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.

Abstract: A method of reducing contamination caused by high intensity heating of metals is taught. Splatter, vapor droplets and particulate matter is collected to avoid return to the melt. An electric field is established in the heating zone to attract the vapor droplets and particles to charged plates.

Abstract: A method of reducing "fall back" contamination caused by high intensity heating of metals is taught. Splatter, vapor droplets and particulate matter resulting from the high intensity heating is repelled to avoid return to the melt. An electric field is established above the heating zone to repel the vapor droplets and particles from at least one charged electrode disposed above the surface where high intensity heat is applied to a metal surface.

Abstract: A clear optical path is provided in a furnace in which high intensity top surface heating is carried out. The path extends through a viewport to the interior of the furnace chamber. The path extends to a clear metal mirror surface and from the mirror surfaced to other portions of the furnace chamber which are not viewable directly through the viewport.

Abstract: A radiation shield assembly is provided for a cryostat having a helium vessel and which inlcudes 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A vent tube which is particularly useful for horizontal cryostat penetration comprises a plurality of conduit sections joined by mating rings which facilitate the incorporation of relatively deep circumferential grooves in the conduit sections. Thermal contact springs, preferably in the form of a single strip are disposed in these circumferential grooves so as to provide a means for transfer of thermal energy from the cryostat interior to the exterior either for general refrigeration requirements or for liquefaction of coolant vapor which may have boiled off from the cryostat interior. The cryostat which incorporates the present invention is particularly useful in housing NMR medical diagnostic imaging magnet and coil systems.

Abstract: 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.