Abstract: Molten metallic material is cast into a mold that is made with a barrier to reduce gas permeability through a mold wall that forms on its innermost side a mold surface for contacting the molten metallic material. The molten metallic material is gravity cast into the mold residing in a furnace in a casting chamber under a first pressure, such as subambient pressure. Then, a gaseous pressure is provided in the casting chamber higher than the first pressure rapidly enough to reduce or eliminate the presence of localized voids in the casting solidified in the mold.

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: An apparatus for use in casting a metal article includes a furnace assembly into which a mold is raised and an annular fluidized bed adjacent to the furnace assembly. The mold is filled with molten metal and lowered into the fluidized bed. The molten metal is solidified in the mold as it is lowered into the fluidized bed. The mold and fluidized bed are then lowered. The fluidized bed is disposed in a container having annular inner and outer walls which are cooled and function as heat sinks. A mold support member may extend through a passage in the annular inner wall of the fluidized bed.

Abstract: Apparatus and method for casting metals and alloys using a pyrometer positioned outside or inside of a casting chamber and relative to a mold heating element in the casting chamber to view a region of a hot melt-filled refractory mold to improve accuracy of the mold temperature readings. The pyrometer is disposed at an elevation outside the casting chamber to view the mold along a viewing path above an induction coil and through an opening in a tubular susceptor disposed about the mold. Alternatively, the tubular susceptor and induction coil both include horizontal openings through which the pyrometer views the melt-filled mold from outside the casting chamber. The pyrometer is positioned to view a uniform profile region of the melt-filled mold having multiple mold cavities as the mold and susceptor are relatively moved.

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 mold support (110) is disclosed for supporting a plurality of molds (109) in a casting apparatus having a first zone for introducing molten material into the molds and a second zone in which the material in the molds can cool. The mold support (110) is capable of relative movement from the first zone to the second zone thereby forming a solidification front in the material in each mold, whereby the solidification front moves through the material as the material solidifies. Each mold (109) defines a main axis (A) along which the solidification front can move and a centrally extending plane (P) perpendicular to the main axis. The mold support (110) comprises carrying means upon which the molds (109) can be disposed.

Abstract: Molds (1) with annular mold parts (2, 3) divided by at least one plane of division (E—E) and forming a plurality of cavities (8) disposed at least substantially radially to a centrifugation axis (A—A), serve for the production of precision castings by centrifugal casting, especially of parts made of materials containing titanium for internal combustion engines, the molds (1) and a casting system being contained in a closed chamber. To automate production, at least one mold part (2, 3) is made to rotate in its own rotational guide, and two mold parts (2, 3) together with the corresponding rotational guides are brought to a closed position for the casting and solidification and to an open position for the removal of the precision castings. When cast, the precision castings are preferably joined together at their radially inward pointing ends by a circumferential ring of the solidified metal and thus a circle of castings can be removed from the opened mold by a manipulating system.

Abstract: An apparatus for use in casting a metal article includes a furnace assembly into which a mold is raised and a fluidized bed adjacent to the furnace assembly. The mold is filled with molten metal and lowered into the fluidized bed. The molten metal is solidified in the mold as it is lowered into the fluidized bed. The mold and fluidized bed are then lowered. The mold may be supported on a grid or support member having openings through which gas and particulate in the fluidized bed can flow. A stirrer member may be moved in the fluidized bed to promote uniform distribution of particulate in the flow of gas. Gas may be conducted from the support member for the mold into a container which holds the fluidized bed. Gas at different pressures may be conducted into the fluidized bed at different locations in the fluidized bed.

Abstract: Fully dense long ingots are produced by the bottom pouring method and apparatus of the present invention. A solidification sequence is achieved which is conducive to eliminating solidification shrinkage and piping. The set-up of the bottom poured ingot molds facilitates a solidification sequence starting from the top and then down the ingot mold and then up the down pour pipe.

Abstract: A thermally highly loaded casting is produced. The casting mold is produced from a slurry using a wax model and a polymer foam which is fixed to the wax model or has been introduced into a cavity. In this way, during the casting process the liquid superalloy also penetrates into the open-cell structure of the casting mold, so that an integral cooling structure is formed during the solidification of the casting. A single-crystal or directionally solidified casting is advantageously produced. It is also conceivable to vary the cell size of the polymer foam, to produce a cooling structure and a base material separately, and to coat the cooling structure with a ceramic protective layer (thermal barrier coating).

Abstract: Tuning of turbine bucket torsional and stripe mode natural frequencies can be effected without altering any turbine bucket physical features, such as weight and/or shape, and without affecting flexure frequencies. The tuning of certain turbine bucket natural frequencies serves to avoid detrimental blade resonance, thus improving the reliability of a gas turbine. The method includes investment casting the turbine bucket with a single crystal alloy, and tuning the natural frequency of the turbine bucket without modifying physical features of the turbine bucket by placing a crystal seed along a desired direction according to a relative orientation of an engine axial direction.

Abstract: A mold for casting a vehicle wheel includes a plurality of mold members that cooperate to define a mold cavity. The mold cavity includes an annular rim cavity for casting a wheel rim and a disc cavity for casting a wheel disc. The mold members define a central axis and have a passageway for introducing molten metal into the rim cavity. The rim cavity has a radial width that changes in a circumferential direction between a maximum width portion of the rim cavity located proximally relative to the passageway, and a minimum width portion of the rim cavity located distally relative to the passageway. In a method for casting a vehicle wheel, a mold as described above is provided. Molten metal is introduced through the passageway into the rim cavity to fill the mold cavity and form a wheel casting. The wheel casting is allowed to cool sufficiently to solidify the metal.

Abstract: A process for producing a casting core which is used for forming within a casting a cavity intended for cooling purposes, through which a cooling medium can be conducted, the casting core having surface regions in which there is incorporated in a specifically selective manner a surface roughness which transfers itself during the casting operation to surface regions enclosing the cavity and leads to an increase in the heat transfer between the cooling medium and the casting.

Abstract: A mold basket, for supporting a mold, for use in a liquid metal bath furnace with an elevator, comprising a flange for suspending the mold basket from the elevator; and a horizontal plate disposed beneath the flange for supporting the mold, wherein the plate is coupled to the flange with a plurality of vertical tie rods.

Abstract: An article, such as an airfoil, is cast by a lost wax investment casting process. The process includes providing a core having a configuration corresponding to the configuration of a space to be formed in the airfoil. The core is at least partially enclosed with a layer of wax. A portion of the layer of wax is removed from the core. The step of removing a portion of the layer of wax from the core includes heating a tubular member and melting a portion of the wax layer by engaging the wax layer with the heated tubular member. Molten wax is conducted away from the core through the heated tubular member. A mold is formed by at least partially coating the wax layer with mold material which extends across the core at the locations where the melted wax was conducted away from the core. The wax layer is removed to form a mold cavity which is filled with molten metal to cast the airfoil.

Abstract: A device for directional solidification of a fused metal, for example a CoCrAlY alloy, which has been poured into a molding shell, by moving the molding shell out of a heating chamber and by immersing the molding shell in a liquid-metal bath serving as a cooling melt with a lower melting-point than the fused metal in the molding shell, for example tin. The liquid-metal bath is enclosed by several current carrying toroidal coils arranged coaxially relative to one another. For the purpose of orienting the stream filament of the agitated fused metal one or more guide plates are arranged in the space between the lateral circumferential surface of the molding shell and the inner wall of the shell containing the liquid-metal bath which is located opposite the molding shell.

Abstract: A grain starter capable of nucleating a multiplicity of grains in a casting is positioned within a mold. The mold is filled with molten metal and a solidification interface is caused to pass from the grain starter through the molten metal by immersing the mold in a cooling bath to form a casting that has a multiplicity of grains nucleated by the grain starter.

Abstract: A gas turbine engine airfoil is cast around a core having a plurality of legs to form matching flow channels in the airfoil. The legs have a tie extending therebetween to maintain alignment. And, the tie is relocated along the core span to reduce differential static pressure of the cooling air across the resulting tie hole formed by the core tie.

Abstract: A method of casting a directionally solidified article such as a component of a gas or steam turbine. The casting is performed in a casting furnace comprising a heating chamber, a liquid cooling bath as a cooling chamber and a shell mold. During casting, shell mold is fed with liquid metal and withdrawn from the heating chamber to the cooling chamber while the interior of the casting furnace is supplied with an inert atmosphere of Ar and/or He in the pressure range of 0.01 to 1 atmosphere, with a preferred range of 0.05 to 0.25 atmosphere. The method can provide improved heat transfer across the shell mold allowing a higher withdrawal rate, reduction in defects and/or improvement in properties of the cast articles.

Abstract: In a casting furnace employing a liquid metal bath to allow directional solidification of an article from a melt, and a method of operating such a furnace, a system is provided for lowering the mold from within a heating chamber into a liquid metal bath situated immediately beneath the heating chamber. An automated system is provided for automatically maintaining the level of the liquid metal bath at a relatively constant position immediately beneath the heating chamber, wherein simultaneously upon the level of the bath having risen due to immersion of the mold within the bath, the bath is lowered to thereby permit the level of the liquid metal bath to be maintained in a substantially fixed position.

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 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: A liquid metal cooled directional solidification process provides improved solidification characteristics at the solidification front. In the process, a mold is filled with molten metal; and a solidification interface is caused to pass through the molten metal by progressively immersing the mold into a cooling liquid. The cooling liquid is a eutectic or near eutectic metal composition. A directional solidification furnace includes a heating furnace, a liquid cooling bath and a mold positioner. The heating furnace has an open bottom end through which a heated mold containing molten metal is lowered from the furnace. The liquid cooling bath comprises a molten eutectic or near eutectic metal composition positioned beneath the open end of the furnace. The mold positioner gradually lowers the heated mold from the furnace, through the open end and immerses the mold into the liquid cooling bath.

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: A method and apparatus for producing large, directionally solidified cast articles having a cast height greater than 200 mm, and preferably greater than 300 mm is described. The casting mold reliability, as well as the casting equipment, is improved by proportioned pouring of a molten superalloy into a casting mold where the mold is protected by suspender elements. The cast articles made by the inventive method are of particular interest to aircraft and power generation equipment, and include, but are not limited to, components such as blades, airfoils, buckets, nozzles, and the like.

Abstract: An article, such as a gas turbine engine mixer, is made by providing a mold structure defining a thin-walled, hollow article, and a base metal that is subject to hot tear cracking when cast in a generally equiaxed polycrystalline form, such as Rene' 108 and Mar-M247. The article is fabricated by introducing the molten base metal into the mold structure, and directionally solidifying the base metal in the mold structure to form a directionally oriented structure. The directionally oriented structure may be formed of a single grain or oriented multiple grains.

Abstract: A method and apparatus are provided for making high purity and preferably oxygen free substantially void free and inclusion free copper castings such as billets from high purity copper. The castings are particularly useful to make sputtering targets used in sputtering deposition processes in the fabrication of electronic components. The method comprises melting high purity copper in a covered crucible using a non-contaminating heating source such as a coil induction furnace. The melted copper in the crucible is solidified using a specially controlled cooling procedure wherein the bottom of the crucible is cooled so that molten copper is maintained on top of solidified and solidifying copper until the copper is solidified.