Abstract: The fluidized bed is formed of particulate material suspended in a flow of gas. A flow of particulate suspended in gas is conducted between a lower end portion of the fluidized bed and an upper end portion of the fluidized bed to cool the upper end portion of the fluidized bed. The flow of particulate suspended in gas may be conducted from a lower end portion of the fluidized bed to an upper end portion of a fluidized bed. Alternatively, the flow of particulate suspended in gas may be conducted from the upper end portion of the fluidized bed to the lower end portion of the fluidized bed. If desired, the flow of particulate suspended in gas may be conducted to the upper end portion of the fluidized bed from a location spaced from the fluidized bed.

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: 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: A layer of hollow spheres is floated on a fluidized bed beneath a furnace. A mold containing molten metal is heated in the furnace to melt the molten metal. The mold is then moved from the furnace through the layer of hollow spheres into the fluidized bed. As the mold moves into the fluidized bed, heat is conducted form the mold and the metal is solidified.

Abstract: A wax article pattern having a cavity corresponding to a cavity in a metal article is provided. The cavity in the wax article pattern is filled with a slurry of ceramic core material. The slurry of ceramic core material is solidified to form a core. The wax article pattern is enclosed by ceramic mold material. The ceramic mold material is solidified to form a mold. The wax pattern is removed from the mold to leave an article mold cavity. The article mold cavity is filled with molten metal which is solidified to form the metal article. A passage in the metal article may be formed by a pin which extends from the wax article pattern into the cavity in the wax article pattern and is enclosed by the slurry of ceramic core material.

Abstract: An apparatus and method for use in casting a metal article includes a mold structure having wall sections with pins extending between the wall sections. The pins have opposite end portions which are embedded in the wall sections of the mold structure to interlock the pins and the wall sections of the mold structure. When molten metal is poured into the mold structure, the molten metal urges the wall sections away from each other. The wall sections are retained against movement relative to each other by the pins. Although the apparatus and method of the present invention can be utilized to cast many different types of articles, the invention is advantageously utilized in the casting of thin metal articles and specifically a thin metal article which is formed as a single crystal.

Abstract: A mold is used to cast an article as a single crystal having selected primary and secondary orientations. The mold includes an article mold having a configuration corresponding to the configuration of the article to be cast. A starter section contains a starter cavity in which one or more crystals form. A seed crystal is disposed in the starter cavity. A crystal selector has a passage which extends between an upper end of the starter and a lower end of the article mold. To promote the growth in the crystal selector passage of a crystal having primary and secondary orientations corresponding to the selected primary and secondary orientations of the article, the longitudinal central axis of the crystal selector passage is disposed in a single plane which is parallel to a plane containing the selected primary orientation axis of the single crystal article and the selected secondary orientation axis of the single crystal article.

Abstract: A mold structure includes an article mold having a mold cavity with a configuration corresponding to the configuration of the article to be cast. A starter section contains a starter cavity in which a plurality of crystals form. A crystal selector has a passage which extends between an upper end of the starter cavity and a lower end of the article mold cavity. To promote the growth in the crystal selector passage of a crystal having primary and secondary orientations corresponding to selected primary and secondary orientations of the article, the crystal selector passage has a portion which slopes downwardly in the direction of solidification of metal along the crystal selector passage. Without the use of a seed crystal, the cast article will have a secondary orientation axis which is almost always within plus or minus 30 degrees of a selected secondary orientation axis.

Abstract: During the casting of reactive metals, the depletion of reactive elements from molten metal in an article mold cavity is prevented by blocking a feeder passage after filling an article mold cavity with the molten metal. To block the feeder passage, a valve member is floated on the molten metal. As the level of the molten metal rises, the valve member moves into sealing engagement with a valve seat. To make a mold structure containing the valve member, the valve member is positioned in a pattern of the mold structure. After covering the pattern with ceramic mold material, the pattern is removed to leave the valve member in the mold structure.

Abstract: A single crystal selector has a passage into which a plurality of crystals grow from a starter cavity and from which a single crystal emerges into an article mold cavity. The single crystal selector passage includes a linear lower vertical portion which extends upwardly away from an end portion on the starter cavity. A linear vertical upper portion of the selector passage extends downwardly from a lower end portion of the article mold cavity. A single bend portion of the selector passage extends between the upper and lower portions of the selector passage. A support element extends upwardly from a lower section of the selector to an upper section of the selector to at least partially support a single bend section of the selector. The single bend portion of the selector passage has a generally circular cross sectional configuration with a diameter which is less than 0.25 inches. The single bend portion of the selector passage extends sidewardly for a distance which is at least 1.

Abstract: An improved mold has a coating of material having a relatively high emissivity. The surface of the coating has an emissivity which is at least twice as great as the emissivity of the surface of the ceramic mold material. When the mold is removed from a furnace chamber, the surface of the coating radiates heat at a relatively high rate. In one embodiment of the invention, the coating is applied to only a portion of the surface of a ceramic mold. In another embodiment of the invention, the coating of material having a relatively high emissivity is applied to only a portion of a crystal selector on a mold for a single crystal article. The relatively high rate of radiation of heat from the coated portion of the crystal selector increases the rate of growth of an adjacent single crystal grain. If desired, the entire mold can be covered with the coating of material having a relatively high emissivity. The coating of material having a high emissivity may be formed of graphite.

Abstract: An improved mold includes an upper mold section having a primary distribution system which is connected with a furnace and a lower mold section which is withdrawn from the furnace on a chill plate. A baffle plate is supported from the primary distribution system. The lower mold section includes a secondary distribution system which is connected in fluid communication with the primary distribution system at separable joints. The secondary distribution system is connected in fluid communication with article molds which are disposed in an annular array. During pouring of molten metal, reaction forces are transmitted to the chill plate from the pour cup through a support post and baffle plate. Once the article molds have been filled with molten metal, the chill plate is lowered. The primary distribution system which is connected to the furnace, remains stationary.

Abstract: An improved apparatus and method is used to cast a plurality of articles in a mold structure having a plurality of article molds disposed in an array having an open central portion. The article molds are filled with molten metal while the mold structure is supported on a chill plate. An inner baffle plate is disposed in the central portion of the array of article molds and retards the transfer of heat from the article molds to the chill plate. The inner baffle plate is supported by a support structure which extends through the chill plate. After the article molds have been filled with molten metal, the chill plate and mold structure are lowered relative to the inner baffle plate to increase the rate of heat transfer from the article molds to the chill plate through the open central portion of the array of article molds. Thereafter, the inner baffle plate and support structure are lowered with the chill plate and mold structure.

Abstract: An improved mold includes an upper mold section having a primary distribution system which is connected with a furnace and a lower mold section which is withdrawn from the furnace on a chill plate. A baffle plate is supported from the primary distribution system. The lower mold section includes a secondary distribution system which is connected in fluid communication with the primary distribution system at separable joints. The secondary distribution system is connected in fluid communication with article molds which are disposed in an annular array. During pouring of molten metal, reaction forces are transmitted to the chill plate from the pour cup through a support post and baffle plate. Once the article molds have been filled with molten metal, the chill plate is lowered. The primary distribution system which is connected to the furnace, remains stationary.

Abstract: In order to maintain fluid tight seals between open ended article mold cavities and a chill plate and to prevent cracking of article molds at connections with a base plate, the base plate has sections which can be moved relative to each other under the effect of thermal expansion forces transmitted from a molten metal distribution system connected with the upper ends of the article molds. The base plate may be formed as one piece with stress concentration areas. During the casting of articles, stresses in the base plate crack the base plate at the areas of stress concentration to form the separate sections of the base plate. The areas of stress concentration can be formed by slots or grooves in the base plate. The areas of stress concentration can also be formed by bodies of expansion material having a greater coefficient of thermal expansion than the ceramic material of the base plate.

Abstract: Method for making a bicast article in which a solid metal preform is positioned in a mold and a molten metal is cast around portions of the preform which are exposed in the mold. In accordance with the present invention, the exposed portions are coated prior to the casting step with a boron containing alloy which is compatible with the preform and with the metal to be cast about it, the boron containing alloy having a melting range below the melting range of either the preform or the cast metal. The alloy also has a major ingredient which is the same as the major ingredient of at least one of the metals to be joined. After solidification of the molten metal in the casting cavity, the resulting bicast article is heat treated at a temperature below the melting range of either the preform or the solidified metal to cause diffusion of boron into the preform and into the solidified metal thereby providing an improved metallurgical bond.