Abstract: A method is provided for casting a gas turbine component having at least a first section and a second section. As per the method, a liquid metal is cast into a casting mold and solidification of the metal is induced by means of controlled cooling. The cooling of the liquid metal in the first section is controlled in such a way that the metal solidifies in a directionally solidified crystal structure or a single-crystal structure. In the second section the cooling is carried out in such a way that it solidifies in a multidirectional crystal structure.

Abstract: A mold package for casting a wheel assembly includes a sand printed drag mold having a cavity with a chill support chamber and a metal chill received in the support chamber. The mold package further includes at least one sand printed mold insert received in the cavity of the sand printed drag mold and a sand printed cope mold coupled to the sand printed drag mold such that a casting cavity for the wheel assembly is created by the exterior inner surfaces of the cope mold, the drag mold and the at least one insert.

Abstract: An investment casting process is provided in which a molten aluminum metal is cast into a refractory mold and thereafter cooled to solidify the metal in the mold. The improvement includes the step of cooling the mold and solidifying the metal therein which is carried out by placing the mold in a chamber adapted to retain a liquid. The mold is mounted in a stationary condition in the chamber. A coolant liquid is introduced into the chamber to immerse the mold in the liquid while maintaining the mold in a stationary condition.

Abstract: A method and apparatus for directionally controlled rapid solidification of a molten metal casting provides modified mold flasks containing mold media defining a mold cavity into which molten metal is poured and thereafter solidified. The mold media is fluid permeable and electrically and thermally conductive so that coolants passing through the media conduct heat away from the molten metal to promote solidification. Apparatus carried upon and within the mold flask allow controlled application of coolants to dissipate heat in a controlled manner to promote solidification in a controlled direction. Ports defined in the flasks, spaces between the mold media particulates and coolant, directionally applied by a movable cooling ring provide controlled directional cooling and castings having improved mechanical characteristics, with greater speed and increased efficiency.

Abstract: In accordance with an exemplary embodiment, a turbine stator component includes a first endwall; a second endwall; a first stator airfoil coupled between the first and second endwalls; and a second stator airfoil adjacent to the first airfoil and coupled between the first and second endwalls. The first stator airfoil has first crystallographic primary and secondary orientations. The second stator airfoil has second crystallographic primary and secondary orientations, the first crystallographic primary and secondary orientations being different from the second crystallographic primary and secondary orientations.

Abstract: A process capable of producing large metallic castings having lengths of one hundred centimeters or more and a unidirectional crystal structure substantially free of freckle defects. The process includes preheating a mold within a heating zone of a directional casting apparatus, pouring a molten metal alloy into a cavity of the mold, and then withdrawing the mold from the heating zone, through a heat shield, and into a cooling zone of the directional casting apparatus to directionally solidify the molten metal alloy within the cavity. The heating and cooling zones establish an axial thermal gradient that defines a solidification front in the molten metal alloy within the cavity. The mold is withdrawn at a withdrawal rate that, in combination with the axial thermal gradient, causes the solidification front to be substantially flat and perpendicular to the withdrawal direction.

Abstract: In the casting of a single crystal component, such as a turbine blade, by the lost wax casting technique, one or more ceramic pieces are positioned on a wax pattern at locations corresponding to parts of the cast component where relatively quick solidification of molten metal may occur during casting. A coating is subsequently formed around the wax pattern to define a mould, whereupon the wax is removed to leave the one or more ceramic pieces within the formed mould.

Abstract: Casting molds suitable for directional solidification processes using a liquid cooling bath include a graded facecoat structure on a mold body. The graded facecoat structure includes an innermost layer and a delamination layer, wherein the delamination layer fractures upon cooling of the molten metal so as to separate the mold body from the innermost layer, which remains in contact with or in close proximity to the metal being cast. Also disclosed are directional solidification processes.

Abstract: A ceramic core used for cast an air cooled turbine rotor blade or stator vane for a gas turbine engine, the ceramic core includes a larger ceramic core piece connected to a smaller ceramic core piece with a number of even smaller cross-over hole forming pieces connecting the larger piece to the smaller piece, and a strain relief slot formed in the larger ceramic core piece adjacent to the cross-over hole forming pieces that prevent the smaller cross-over hole pieces from breaking during the casting process from relative movement of the larger ceramic core piece with respect to the smaller ceramic core piece. The strain relief slot can be used to cast a rotor blade or a stator vane.

Abstract: A system for manufacturing a wheel includes a cope mold portion comprising internal cope mold walls and a drag mold portion comprising internal drag mold walls. The internal walls define at least in part perimeter boundaries of a wheel cavity. The wheel cavity comprises a cavity center portion configured to form a wheel center portion of a wheel after solidification of a molten alloy in the cavity center portion, a cavity plate portion configured to form a wheel plate portion of the wheel after solidification of a molten alloy in the cavity plate portion, and a cavity flange portion configured to form a wheel flange portion of the wheel after solidification of a molten alloy in the cavity flange portion. The system includes a chill component configured to provide directional solidification from the cavity flange portion toward the cavity plate portion of molten alloy in the wheel cavity.

Abstract: A method of producing a component wherein a directionally solidified columnar grained cast superalloy material is heat treated such that a secondary phase of the alloy is only partly solved, thereby providing improved transverse stress rupture strength compared to fully solved alloys.

Abstract: A casting process and apparatus for producing directionally-solidified castings, and castings produced therewith. The process entails applying a facecoat slurry to a surface within a mold cavity to form a continuous solid facecoat on the surface, introducing a molten metal alloy into the mold cavity so that the molten metal alloy contacts the facecoat, and then immersing the mold in a liquid coolant to cool and solidify the molten metal alloy and form a casting of the metal alloy, during which an oxide layer forms on the casting surface. The facecoat is sufficiently adherent to the oxide layer such that at least a portion of the facecoat detaches from the mold surface and remains tightly adhered to the casting surface in the event the casting contracts during cooling. The facecoat contains at least 60 weight percent of a first phase of yttria, and the balance of the facecoat is a binder phase of an inorganic material.

Abstract: A process for manufacturing a single-crystal turbomachine nozzle guide vane including an airfoil between two platforms is disclosed. The process includes pouring molten metal into a shell mold followed by directional solidification from a single crystal provided by a single-crystal grain provider device placed in the mold and having a predetermined orientation coinciding with the vertical. The volumes of the mold forming the platforms are oriented in a plane parallel to the vertical direction of the single crystal. The single-crystal grain providing device emerges in a grain duct forming a connection between the device and the lower ends of the platforms. The grain duct is shaped to present two branches for feeding the platforms and a web-shaped volume extending between the feed branches, the platforms and a lower edge of the airfoil. The upper edge of the volume forming the airfoil is inclined to the horizontal direction.

Abstract: An apparatus and method for casting an alloy using a unidirectional casting technique. The apparatus includes a mold adapted to contain a molten quantity of an alloy, a primary heating zone adapted to heat the mold and the molten alloy therein to a temperature above the liquidus temperature of the alloy, a cooling zone adapted to cool the mold and molten alloy therein to a temperature below the solidus temperature of the alloy and thereby yield the unidirectionally-solidified casting, and an insulation zone between the primary heating zone and the cooling zone. The apparatus also has a secondary heating zone separated from the insulation zone by the primary heating zone. The secondary heating zone maintains the mold and the molten alloy therein at a temperature below the liquidus temperature of the alloy. The temperatures within the primary and secondary heating zones are individually set and controlled.

Abstract: A system for producing cast components from molten metal. One form of the present invention includes a system for the precision pouring of molten metal within a casting mold. The precision pouring system is driven by a pressure differential.

Abstract: During casting of metal articles, a mold is moved into a body or bath of molten metal. The mold is moved into a container which contains a portion of the body of molten metal. Heat is transferred at a first rate from the mold to a first portion of the body of molten metal disposed above the container. Heat is transferred at a second rate from the mold to the second portion of the body of molten metal at least part of which is disposed in the container. The container retards movement of molten metal relative to the mold to effect an increase in the temperature of the molten metal in the container and thereby retards transfer of heat from a portion of the mold disposed in the container to the body of molten metal. The mold enters the container through an opening at the upper end portion of the container. One or more additional openings may be provided at the lower end portion of the container.

Abstract: An apparatus and method for casting an alloy using a unidirectional casting technique. The apparatus includes a mold adapted to contain a molten quantity of an alloy, a primary heating zone adapted to heat the mold and the molten alloy therein to a temperature above the liquidus temperature of the alloy, a cooling zone adapted to cool the mold and molten alloy therein to a temperature below the solidus temperature of the alloy and thereby yield the unidirectionally-solidified casting, and an insulation zone between the primary heating zone and the cooling zone. The apparatus also has a secondary heating zone separated from the insulation zone by the primary heating zone. The secondary heating zone maintains the mold and the molten alloy therein at a temperature below the liquidus temperature of the alloy. The temperatures within the primary and secondary heating zones are individually set and controlled.

Abstract: A slurry suitable for forming facecoats, facecoats formed by such a slurry, and processes using such facecoats. The slurry is formed of a particulate refractory material, an aqueous suspension containing a particulate inorganic binder, a thixotropic organic binder, a dispersant, and possibly optional constituents excluding particulate refractory materials and inorganic binders. The particulate refractory material constitutes at least about 60 weight percent of the slurry and consists essentially of yttria. The aqueous suspension containing the particulate inorganic binder constitutes at most about 35 weight percent of the facecoat slurry. The dispersant is present in the slurry in an amount sufficient to stabilize the slurry at a pH of up to about 10, and has the general formula Hx[N(CH2)yOH]z, where x has a value of 0, 1 or 2, y has a value of 1 to 8, and z=3?x.

Abstract: A system for producing cast components from molten metal. One form of the present invention includes a system for the precision pouring of molten metal within a casting mold. The precision pouring system is driven by a pressure differential.

Abstract: A molding process utilizes a seed with a columnar grain structure for defining a desired grain structure in a completed casting. The seed is received within a seed cavity of a mold. The molten material adopts the orientation of the columns defined within the seed during solidification to form a completed molded article having a desired columnar grain structure.

Abstract: A method of mitigating against thermal contraction induced cracking during casting of a super Ni alloy, the method comprising: pouring liquid alloy into a mould such that liquid alloy is present in a feeder of said mould; and inducing an electrical current in alloy in said feeder to reduce a rate of cooling of alloy in said feeder.

Abstract: A method of casting metal articles includes providing a plurality of interconnected support sections. Article mold sections are positioned on the support sections. After article mold cavities, have been filled with a molten metal which is at a first temperature, the support sections and a body of a second molten metal are moved relative to each other while the body of a second molten metal is at a temperature which is less than the first temperature. Space extending between side surfaces of the support sections and between side portions of the article mold sections is filled with the second molten metal during movement between the support sections and the body of a second molten metal. A layer of insulating material may be provided above the body of a second molten metal. A baffle may be provided between a container holding the body of a second molten metal and a furnace assembly.

Abstract: The object of the present invention is to provide a casting method capable of simultaneously attaining the shortening of cycle time and the improvement in casting quality. The pressure allowing the molten metal level to go up to the positions of from P0 to P4 is applied to the molten metal within a molten metal reservoir 1. Then, the pressure of P4 is maintained for a predetermined time. During this time, the molten metal which comes into contact with an upper die 4 is cooled earlier than the molten metal being in contact with another die. Through this cooling the molten metal shrinks. However, since the pressure of P4 is maintained, the molten metal is supplied from the lower side to a shrunk portion, so as not to cause shrinkage cavity or underfill.

Abstract: A directional solidification furnace comprises a crucible assembly including a crucible for containing a melt having walls and a base with an opening therein, a crucible support for supporting the crucible, and a lid covering the crucible. A plate is received in the opening in the base. The plate has a higher thermal conductivity than that of the base. The base can include a composite having an additive such that the composite base has a higher thermal conductivity than a comparable without the additive.

Abstract: To cast one or more metal articles, a mold structure is positioned on a support with an anchor extending upward from the support into the mold structure. The mold structure and anchor are interconnected by a retainer which extends through a portion of the mold structure into the anchor. When the mold structure is immersed in a cooling bath, force is transmitted between the mold structure and anchor to retain the mold structure against movement relative to the support.

Abstract: Rhenium-free nickel based alloys are provided. More particularly, the alloys comprise preferred levels and ratios of elements so as to achieve good high temperature strength of both gamma matrix phase and gamma prime precipitates, as well as good environmental resistance, without using rhenium. When cast and directionally solidified into single crystal form, the alloys exhibit oxidation resistance better than or comparable to rhenium-bearing single-crystal alloys, and creep rupture life comparable to rhenium-bearing single-crystal alloys. Further, the alloys can be processed by directional solidification into articles in single crystal form or columnar structure comprising fine dendrite arm spacing, e.g., less than 400 ?m, if need be, so that further improvements in mechanical properties in the articles can be seen.

Abstract: An apparatus and process are provided for casting liquid metals into molds in a casting furnace comprising a controlled environment melt chamber and a mold lock chamber. A mold is supplied to the controlled environment melt chamber for a pour, and removed from the same chamber via a mold lock chamber. A mold transport system moves the mold through the mold lock chamber. The mold transport system comprises a rotary screw drive, a cylinder screw drive, or hydraulic drive located external to the furnace. Alternatively the mold transport system comprises a rack and worm screw drive.

Abstract: Systems and methods for reducing the potential for riser backfilling during investment casting are provided. In this regard, a representative method for performing investment casting includes: providing a mold having an opening communicating with an interior, the interior having a part cavity and a riser; providing an insert; and using the insert to form a physical barrier to reduce a potential for molten metal to backfill into the riser while the molten metal is introduced into the interior of the mold via the opening.

Abstract: A high modulus component, such as an aircraft engine turbine blade, is formed from a base metal that has a high modulus crystallographic orientation that is aligned with the primary, i.e. radial, direction of the turbine blade. The base metal is Ni, Fe, Ti, Co, Al, Nb, or Mo based alloy. Alignment of a high modulus direction of the base metal with the primary direction provides enhanced high cycle fatigue life.

Abstract: A castable high temperature aluminum alloy is cast by controlled solidification that combines composition design and solidification rate control to synergistically enhance the performance and versatility of the castable aluminum alloy for a wide range of elevated temperature applications. In one example, the aluminum alloy contains by weight approximately 1.0-20.0% of rare earth elements that contribute to the elevated temperature strength by forming a dispersion of insoluble particles via a eutectic microstructure. The aluminum alloy also includes approximately 0.1 to 15% by weight of minor alloy elements. Controlled solidification improves microstructural uniformity and refinement and provides the optimum structure and properties for the specific casting condition. The molten aluminum alloy is poured into an investment casing shell and lowered into a quenchant at a controlled rate.

Abstract: A system for producing cast components from molten metal. One form of the present invention includes a system for the precision pouring of molten metal within a casting mold. The precision pouring system is driven by a pressure differential.

Abstract: A hybrid cast component (10) including both a columnar grained region (12) and a single crystal region (14) integrally formed and joined along a metallurgical boundary (32) in a single casting operation without the need for any weld or braze. A gas turbine blade formed as such may include a columnar grained airfoil and a single crystal platform without any necessity for a thermally formed joint at the blade fillet area.

Abstract: A process capable of producing large metallic castings having lengths of one hundred centimeters or more and a unidirectional crystal structure substantially free of freckle defects. The process includes pouring a molten metal alloy into a preheated mold within a heating zone, withdrawing the mold from the heating zone, through a heat shield, and into a cooling zone to directionally solidify the molten metal alloy, and then cooling the mold to produce the casting and the unidirectional crystal structure thereof. The heat shield operates as a barrier to thermal radiation between the heating zone and the cooling zone, and the mold is withdrawn at a rate that, in combination with the heat shield, maintains a thermal gradient to solidify the molten metal alloy and form primary dendrite arms having an average spacing therebetween of about 150 to about 500 micrometers.

Abstract: Method for forming directionally solidified articles in tightly packed mold cavities withdrawn into liquid metal cooling bath. The withdrawal rate and the spacing between adjacent mold cavities cooperate to provide a high thermal gradient. The cast articles exhibit primary dendrite arm spacing of between about 6 to about 12 mils (about 150-300 microns).

Abstract: A castable high temperature aluminum alloy is cast by controlled solidification that combines composition design and solidification rate control to synergistically enhance the performance and versatility of the castable aluminum alloy for a wide range of elevated temperature applications. In one example, the aluminum alloy contains by weight approximately 1.0-20.0% of rare earth elements that contribute to the elevated temperature strength by forming a dispersion of insoluble particles via a eutectic microstructure. The aluminum alloy also includes approximately 0.1 to 15% by weight of minor alloy elements. Controlled solidification improves microstructural uniformity and refinement and provides the optimum structure and properties for the specific casting condition. The molten aluminum alloy is poured into an investment casing shell and lowered into a quenchant at a controlled rate.

Abstract: Provided is a process for producing a purified silicon by cutting off a crude silicon region, without determining the aluminium concentration in a directionally-solidified silicon. In the process of the invention, a standard solidification fraction (f0) satisfying the following formula (1) and formula (2) is obtained from the predetermined maximum level of aluminium concentration (C10max), the temperature gradient (T) and the solidification speed (R), and the directionally-solidified silicon is cut at the part having a solidification fraction (f) in the solidification step corresponding to f0. k = { K 1 × Ln ? ( R ) + K 2 } × { K 3 × exp ? [ K 4 × R × ( K 5 × C 2 + K 6 ) ] } × { K 7 × T + K 8 } - K 9 ( 1 ) [wherein k is a coefficient selected from a range of from 0.9 times to 1.

Abstract: A method and apparatus for preparing and delivering various types of carbon and microalloy steel, free of oxygen with abundance of nuclei, when cast producing ultra fine grain steel free of internal defeats with excellent quality. A horizontal sealed table caster has a chamber, containing a suitable atmosphere for casting, with a tube connecting to a tundish so as to allow a liquid to flow into the chamber. The liquid metal is captured on a cooling belt along the bottom of the chamber and is maintained as a specific width and depth. The cooling belt serves as a heat sink causing the liquid metal to solidify from the bottom up, allowing inclusions to migrate to the surface of the steel. A layer of liquid metal is maintained on top of the solidifying steel until the solidification reaches the surface. The belt moves the solid metal toward the exit of the chamber.

Abstract: Previously a number of techniques have been used in order to form single crystal or pre-determined crystallography components and articles. Each one of these techniques has its own particular problems, including susceptibility to error. By utilisation of a bi-crystal experiment to determine melt-back length LM and by consideration of the ingress distance d from potential initiation nucleation points on a perimeter of a seed crystal, it is possible to determine a maximum ingress length d. By ensuring that the maximum ingress length d is less than or equal to a seed crystal diameter R, it is possible to project locus from potential nucleation points C1, C2 in terms of potential radii for stray grain propagation. As the seed crystal will have a known crystalline orientation, it will be possible to consider two divergent growth curves of the crystal in terms of the stray grains propagating from the point C1, C2.

Abstract: A Method of casting includes providing a mold having one or more article mold cavities. The mold is moved into a furnace. While the mold is in the furnace, the mold is filled with molten metal. After the mold has been removed from the furnace, a heater is positioned adjacent to the mold and heat is transmitted from the heater to the mold. The heater may include electrically energizable resistance type heating elements, or a source of radiant energy or a gas burner.

Abstract: A mold assembly for a liquid metal cooled directional solidification furnace having a cooling chamber provided with liquid metal and a heating chamber includes a mold member having a main body portion that defines an interior mold cavity. The mold member is adapted to be positioned in the heating chamber. The mold assembly also includes a chill-plate formed from a material having a thermal diffusivity a 600° K greater than approximately 10 E-6 m2/s, inert to at least one of molten tin and molten aluminum and adapted to be at least partially immersed in the liquid metal. The chill-plate includes a main body portion having a first surface extending to a second surface through an intermediate portion. The chill-plate is adapted to establish a thermal gradient between the mold member and the heating chamber.

Abstract: Molten metal is injected uniformly into a horizontal mold from a feed chamber in a horizontal or vertical direction at a controlled rate, directly on top of the metal already within the mold. A cooling medium is applied to the bottom surface of the mold, with the type and flow rate of the cooling medium being varied to produce a controlled cooling rate throughout the casting process. The rate of introduction of molten metal and the flow rate of the cooling medium are both controlled to produce a relatively uniform solidification rate within the mold, thereby producing a uniform microstructure throughout the casting, and low stresses throughout the casting.

Abstract: An apparatus and process are provided for casting liquid metals into molds in a casting furnace comprising a controlled environment melt chamber and a mold lock chamber. A mold is supplied to the controlled environment melt chamber for a pour, and removed from the same chamber via a mold lock chamber. A mold transport system moves the mold through the mold lock chamber. The mold transport system comprises a rotary screw drive, a cylinder screw drive, or hydraulic drive located external to the furnace. Alternatively the mold transport system comprises a rack and worm screw drive.

Abstract: Molten metal is injected uniformly into a horizontal mold from a feed chamber in a horizontal or vertical direction at a controlled rate, directly on top of the metal already within the mold. A cooling medium is applied to the bottom surface of the mold, with the type and flow rate of the cooling medium being varied to produce a controlled cooling rate throughout the casting process. The rate of introduction of molten metal and the flow rate of the cooling medium are both controlled to produce a relatively uniform solidification rate within the mold, thereby producing a uniform microstructure throughout the casting, and low stresses throughout the casting.

Abstract: A system for producing cast components from molten metal. One form of the present invention includes a system for the precision pouring of molten metal within a casting mold.

Abstract: An investment casting process that enables directionally solidified tip shrouded turbine blades or buckets to have a continuous grain structure that extends through the tip shroud in addition to increasing the quantity of grains in the root of the part.

Abstract: A hollow airfoil is fabricated by providing a casting mold assembly including a casting mold, a casting core, and a standoff spacer that prevents the casting core from contacting the casting mold to define a casting space. A first nickel-base superalloy is cast into the casting space and solidified to form the hollow airfoil. The presence of a through-hole extending through a wall of the hollow airfoil is identified, and the through-hole is closed by welding using a second nickel-base superalloy, without using any freestanding closure element.

Abstract: A ceramic core for use in casting an article such as for example an airfoil, wherein the ceramic core has a pocket located at or near a region of the core that is otherwise associated with occurrence of a localized casting defect in the cast article. A covering is disposed on the core to cover the pocket and provide core outer surface features.

Abstract: A fugitive pattern assembly is made by preforming one or more fugitive patterns of an article to be cast, placing the preformed patterns in an injection die, and injecting fluid gating material into the die to form gating connected to the patterns. The fugitive patterns are disposed in end-to-end and/or side-by-side relation and are interconnected by the gating.

Abstract: Molten metal is injected uniformly into a horizontal mold from a feed chamber in a horizontal direction at a controlled rate, directly on top of the metal already within the mold. A cooling medium is applied to the bottom surface of the mold, with the type and flow rate of the cooling medium being varied to produce a controlled cooling rate throughout the casting process. The rate of introduction of molten metal and the flow rate of the cooling medium are both controlled to produce a relatively uniform solidification rate within the mold, thereby producing a uniform microstructure throughout the casting, and low stresses throughout the casting.

Abstract: A ceramic core for use in casting an article such as for example an airfoil, wherein the ceramic core has a pocket located at or near a region of the core that is otherwise associated with occurrence of a localized casting defect in the cast article. A covering is disposed on the core to cover the pocket and provide core outer surface features.