Abstract: A ceramic investment shell mold is reinforced with a carbon based fibrous reinforcement having an extremely high tensile strength that increases as the mold temperature is increased especially within the range of casting temperatures employed for casting large directionally solidified industrial gas turbine components. The carbon based fibrous reinforcement is wrapped or otherwise positioned around the repeating ceramic slurry/stucco layers forming the intermediate thickness of the shell mold wall. The reinforced shell mold can be used to cast large directionally solidified industrial gas turbine components with accurate dimensional control.

Abstract: A method for firing a ceramic core includes placing the ceramic core on a setter, placing at least one flexible refractory bag containing refractory particulates on the core to apply a force on the core toward the setter during firing, and then heating the ceramic core on the setter to an elevated superambient firing temperature. Heating of the ceramic core with the flexible weight bag(s) thereon conforms the core to a surface of the setter to reduce distortion of the core and improve yields of cores within preselected dimensional tolerances.

Abstract: A particulate material transfer device comprises a tubular body having a passage with an entrance to receive particulate material and an exit for discharging material and an annular chamber about the body in which a travelling member is disposed for movement about the body in a manner to impart vibrations thereto. A fluid inlet supplies pressurized air to the chamber to cause the travelling member to move about the body to impart vibrations thereto. A plurality of fluid discharge openings extend from the chamber to the passage to discharge pressurized fluid toward the exit to transfer material from the entrance through the passage toward the exit.

Abstract: A ceramic investment shell mold is reinforced with a carbon based fibrous reinforcement having an extremely high tensile strength that increases as the mold temperature is increased especially within the range of casting temperatures employed for casting large directionally solidified industrial gas turbine components. The carbon based fibrous reinforcement is wrapped or otherwise positioned around the repeating ceramic slurry/stucco layers forming the intermediate thickness of the shell mold wall. The reinforced shell mold can be used to cast large directionally solidified industrial gas turbine components with accurate dimensional control.

Abstract: A multi-wall ceramic core assembly and method of making same wherein a plurality of individual thin wall, arcuate (e.g. airfoil shaped) core elements are formed in respective master dies to have close tolerance mating locating features that substantially prevent penetration of molten metal between the interlocked features during casting, the individual core elements are fired on ceramic supports to have integral locating features, the prefired core elements are assembled together using the locator features of adjacent core elements, and the assembled core elements are held together using a fugitive material. The multi-wall ceramic core assembly so produced comprises the plurality of spaced apart thin wall, arcuate core elements and located by the mated close tolerance locating features.

Abstract: Coating temperature during vapor deposition of a ceramic coating on a substrate in a coating box or enclosure is maintained by means of a heat release cover or lid on the coating enclosure and movable in response to temperature in the coating enclosure exceeding a predetermined value so as to release excess heat from the enclosure to maintain coating temperature within an appropriate range.

Abstract: Coating temperature during vapor deposition of a ceramic coating on a substrate in a coating box or enclosure is maintained by means of a heat release cover or lid on the coating enclosure and movable in response to temperature in the coating enclosure exceeding a predetermined value so as to release excess heat from the enclosure to maintain coating temperature within an appropriate range.

Abstract: Method of making a ceramic core for casting an industrial gas turbine engine airfoil having a large airfoil pitch by forming a precursor core (chill) of smaller dimensions than the final desired ceramic core, firing the chill, applying a thin ceramic skin to the fired chill to form a coated core of final dimensions, and then firing the coated core. Firing of the thin ceramic skin reduces airfoil pitch shrinkage resulting from the latter firing operation to reduce overall core dimensional tolerance variations.

Abstract: Spraycasting method involves directing an atomized metal or alloy spray at a collector disposed in a spray chamber and controlling temperature of the spray in flight in the spray chamber and of the atomized metal or alloy as it is deposited on the collector by a spray chamber pressure control technique that involves in-situ evacuation of the spray chamber during spray deposition to a maintain spray chamber gas partial pressure less than about 400 torr. Such low spray chamber gas partial pressure provides a higher temperature of the atomized spray in flight in the spray chamber and of the sprayed material as it is deposited on a collector in the spray chamber effective to reduce deposit porosity, reduce grain layering or banding, and provide a uniform grain through the thickness of the deposit.

Abstract: A CVD outwardly grown platinum aluminide diffusion coating on a nickel or cobalt base superalloy substrate wherein the platinum modified aluminide diffusion coating is modified to include silicon, hafnium, and optionally zirconium and/or other active elements (e.g. Ce, La, Y, etc.) each in a concentration of about 0.01 weight % to about 8 weight % of the outer additive (Ni,Pt)(Al,Si) layer of the coating. A particular coating includes about 0.01 weight % to less than 2 weight % of each of silicon, hafnium, and zirconium in the outer additive layer, preferably with a Hf/Si ratio less than about 1 and, when Zr also is present, a Hf+Zr/Si ratio of less than about 1. A coating microstructure is provided characterized by an inner diffusion zone or region adjacent the substrate and the outer additive (Ni,Pt)(Al,Si) layer including hafnium silicide second phase particles or regions dispersed throughout the outer additive layer of the coating.

Abstract: Method as well as apparatus for DS casting using a multi-stage thermal baffle disposed proximate a lower end of a DS casting furnace. The thermal baffle comprises a fixed primary baffle disposed at the lower end of the casting furnace and a secondary baffle initially releasably disposed adjacent and below the primary baffle prior to withdrawal of the melt-filled mold from the casting furnace. The primary baffle includes a primary aperture oriented perpendicular to the mold withdrawal direction and having a cross-sectional configuration tailored to accommodate a relatively large exterior region or profile of the melt-filled mold, such as a relatively wide platform region of a mold for making a turbine blade or vane.

Abstract: Melt delivery system and method including a first melting chamber and a laterally adjacent second melt pour chamber arranged side-by-side to one another with a suitable isolation valve therebetween. A melting/melt delivery system is includes a transport mechanism having a horizontally translatable carriage disposed on a carriage support frame. A shaft mechanism is disposed on the carriage for rotation relative thereto and for carrying a melting vessel in a manner that the melt-filled vessel can be horizontally translated from the melting chamber where a charge is melted in the vessel to the adjacent mold pour chamber where the melt is poured into a casting mold or vessel by rotation of the shaft mechanism. The carriage is translated by an actuator on the carriage support frame, and the shaft mechanism is independently rotated by an actuator on the carriage.

Abstract: Method as well as apparatus for DS casting using a multi-stage thermal baffle disposed proximate a lower end of a DS casting furnace. The thermal baffle comprises a fixed primary baffle disposed at the lower end of the casting furnace and a secondary baffle initially releasably disposed adjacent and below the primary baffle prior to withdrawal of the melt-filled mold from the casting furnace. The primary baffle includes a primary aperture oriented perpendicular to the mold withdrawal direction and having a cross-sectional configuration tailored to accommodate a relatively large exterior region or profile of the melt-filled mold, such as a relatively wide platform region of a mold for making a turbine blade or vane.

Abstract: Method and apparatus for directional solidification of molten metal using a general horizontally oriented mold initially positioned in a casting furnace. The mold is filled with molten metal through a mold pour cup located on an upper region of the mold and a pour cup runner that enters the mold at location proximate a grain selection passage. The melt filled mold initially is withdrawn from the casting furnace to solidify the molten metal at the location where the pour cup runner enters the mold. The melt filled mold then is withdrawn while the mold is rotated about its horizontal axis to reduce segregation of alloying elements in the solidifying molten metal. Initial solidification of molten metal at the entry of the pour cup runner to the mold prevents molten metal from flowing out of the mold through the pour cup when the mold is subsequently rotated.

Abstract: Method and apparatus for directional solidification of molten metal employs a generally horizontally oriented mold initially positioned in a casting furnace. The mold residing on a chill is filled with molten metal through a mold pour cup located on an upper region of the mold. The mold is withdrawn from the casting furnace to effect directional solidification. As the molten metal filled mold is withdrawn, the mold is oscillated about a general horizontal axis within an angular range of up to about 180 degrees. Such limited angle oscillation during mold withdrawal reduces segregation of alloying elements in the solidifying molten metal and prevents molten metal from leaving the mold through the pour cup.

Abstract: Method for removing a ceramic core from a casting in a relatively rapid manner wherein the casting and a fluid spray nozzle are disposed in a manner to expose a region of the core to a core dissolving fluid discharge of the nozzle and a core dissolving fluid is discharged from the nozzle toward the core region to contact the core region and dissolve core material therefrom and progressively from further regions of the core within the casting as they become exposed as core material is progressively removed. The discharge of fluid from the nozzle can be interrupted periodically to allow dissolved core material and fluid to drain from inside the casting or, alternately, the casting and nozzle can be relatively moved so that the casting can drain and/or forced air can be directed at the casting to this same end at a location spaced apart form the nozzle.

Abstract: Method of making a casting by investment casting of a metal or alloy, especially titanium and its alloys, in a ceramic investment shell mold in a manner to provide enhanced x-ray detectability of any sub-surface ceramic inclusions that may be present below exterior surfaces of the casting. The method involves forming a ceramic mold facecoat and/or back-up layer including erbia or other x-ray or neutron-ray detectable ceramic component. The facecoat/back-up layer is/are formed using a ceramic slurry comprising erbia and other optional ceramic particulates, an inorganic binder, and an inorganic pH control agent. The slurry is applied to a pattern of component to be cast to form the mold. A metal or alloy is cast in the mold, and the solidified casting is removed from the mold. The casting is subjected to radiography to detect any sub-surface ceramic inclusions below the exterior surface thereof not detectable by visual inspection of the casting.

Abstract: Machineable nickel base alloy casting, consisting essentially of, in weight %, about 12.5% to 15% Cr, about 9.00% to 10.00% Co, about 3.70% to 4.30% Mo, about 3.70% to 4.30% W, about 2.80% to 3.20% Al, about 4.80% to 5.20% Ti, about 0.005% to 0.02% B, up to about 0.10% Zr, and balance essentially Ni and carbon below about 0.08 weight % to improve machinability while retaining alloy strength properties after appropriate heat treatment.

Abstract: A solid charge of metal or alloy is placing in a crucible melting chamber defined by a monolithic refractory tubular sleeve disposed on a water cooled metallic base, an energizing induction coil disposed about the sleeve to inductively heat the solid charge to a molten state in the melting chamber including forming a skull of solidified metal or alloy on inner surfaces of the sleeve and base to confine the molten charge, and removing the molten charge from the melting chamber, leaving the skull in place on the inner surfaces of the sleeve and base. The crucible can be reused in melting another solid charge of metal or alloy after the molten charge is removed.

Abstract: Melt delivery system and method including a first melting chamber and a laterally adjacent second melt pour chamber arranged side-by-side to one another with a suitable isolation valve therebetween. A melting/melt delivery system is includes a transport mechanism having a horizontally translatable carriage disposed on a carriage support frame. A shaft mechanism is disposed on the carriage for rotation relative thereto and for carrying a melting vessel in a manner that the melt-filled vessel can be horizontally translated from the melting chamber where a charge is melted in the vessel to the adjacent mold pour chamber where the melt is poured into a casting mold or vessel by rotation of the shaft mechanism. The carriage is translated by an actuator on the carriage support frame, and the shaft mechanism is independently rotated by an actuator on the carriage.