Abstract:
A method of making a composite core includes forming first and second cores of refractory metal and ceramic material. Each of the first and second cores is formed with two layers of a material. The layers are bonded together to form a laminate master pattern, and a flexible mold is formed around the pattern. The pattern is removed from the flexible mold, and slurry material, either pulverulent refractory metal material or ceramic material, is poured into the flexible mold. The slurry material is sintered to form each core. The first core is used as an insert while making the second core to create a final composite core.
Abstract:
A method of manufacturing a heat shield panel assembly is provided. The method including: injecting melted wax into a negative cavity of a heat shield panel, the heat shield panel including one or more orifices; allowing the wax to solidify to form a positive pattern of the heat shield panel; removing the positive pattern from the negative cavity; coating the positive pattern with a ceramic; melting the positive pattern away from the ceramic, the ceramic having a cavity forming a second negative cavity of the heat shield panel; pouring melted metal into the cavity; allowing metal in the cavity to solidify to form the heat shield panel; removing the ceramic from the heat shield panel; and forming each of one or more threaded studs separately from the heat shield panel, each of the one or more threaded studs including a stud portion and a thread portion simultaneously formed.
Abstract:
A method of fabricating a casting is provided. The method includes creating a mixture of ceramic powder and a binder, pouring the mixture around sacrificial patterns, executing a first thermal treatment to set the mixture into a solid mold without damaging the sacrificial patterns, executing a second thermal treatment to remove the sacrificial patterns without removing any of the binder from the solid mold, executing at least one of a third thermal treatment and a chemical treatment to remove a quantity of the binder to transform the solid mold into a solid breakaway mold and pouring molten metallic material into the solid breakaway mold.
Abstract:
A method of investment casting includes casting a liquid nickel- or cobalt-based superalloy in an investment casting mold. The superalloy includes an yttrium alloying element that is subject to reactive loss during the casting. Loss of the yttrium is limited by using a zircon-containing facecoat on a refractory investment wall in the investment casting mold. The facecoat contacts the liquid nickel- or cobalt-based superalloy during the casting. Prior to the casting, a zircon-containing slurry is used to form the facecoat. After solidification of the nickel- or cobalt-based superalloy, the refractory investment wall is removed from the solidified superalloy.
Abstract:
A method for die casting a component includes inserting at least one sacrificial core into a die cavity of a die comprised of a plurality of die elements. Molten metal is injected into the die cavity. The molten metal is solidified within the die cavity to form the component. The plurality of die elements are disassembled from the component, and the at least one sacrificial core is destructively removed from the component.
Abstract:
A system and methods are provided for removing core elements of cast components. In one embodiment, a method includes controlling a first high temperature autoclave cycle for a cast component in a vessel with a first solution concentration to remove at least a first portion of core elements, wherein the first solution concentration, temperature and pressure in the vessel are controlled to expose one or more casting pins in the cast component. The method may also include controlling a second high temperature autoclave cycle for the cast component in the vessel with second solution concentration, wherein the second solution concentration, temperature and pressure in the vessel during the second high temperature autoclave cycle are controlled to loosen one or more of the casting pins from the cast component, and controlling one or more low temperature autoclave cycles to remove core and casting pins from the cast component.
Abstract:
High modulus turbine shafts and high modulus cylindrical articles are described as are the process parameters for producing these shafts and cylindrical articles. The shafts/articles have a high Young's modulus as a result of having high modulus crystal texture along the longitudinal axis of the shaft/article. The shafts are produced from directionally solidified seeded single crystal cylinders that are axisymmetrically hot worked before a limited recrystallization process is carried out at a temperature below the recrystallization temperature of the alloy. The disclosed process produces an intense singular texture and results in shaft or cylindrical article with a Young's modulus that is at least 40% greater than that of conventional nickel or iron alloys or conventional steels.
Abstract:
A high-temperature die casting die includes a first die plate with a first recess and a second die plate with a second recess, the first and second recesses defining a main part cavity and gating. A grain selector is in fluid communication with the main cavity, and an in situ zone refining apparatus is adapted to apply a localized thermal gradient to at least one of the first and second die plates. The localized thermal gradient and the at least one die plate are movable relative to each other so as to apply the localized thermal gradient along a first direction extending from the grain selector longitudinally across the main part cavity.
Abstract:
A method for desulfurizing a metal alloy comprises heating the metal alloy to a molten state. A gaseous desulfurizing compound is bubbled through the molten alloy to form a solid sulfur-containing waste phase and a molten reduced-sulfur alloy phase. The solid waste phase and the molten reduced-sulfur alloy phase are separated. The gaseous desulfurizing compound includes a constituent element selected from the group: alkali metals, alkaline earth metals, and rare earth metals.
Abstract:
A method to manufacture reticulated metal foam includes coating a precursor in a molten wax to increase ligament thickness; and investment coating the molten wax coated precursor with a ceramic plaster.