Abstract: A system and method for directionally casting an elongated device are provided. The method includes orienting a mold within a furnace such that a first portion of the mold points downward. The first portion of the mold defines a space within the mold used to form a first end of the device. The first end of the device, when formed, has a greater mass than a second end of the device. The method also includes filling the mold with molten metal and lowering the mold out of the furnace into a liquid metal bath to immerse the first portion of the mold in the liquid metal bath. The method includes concurrently lowering the mold and the liquid metal bath to cool the molten metal.

Abstract: An alloy casting having a protective layer disposed on a surface of the casting is provided. The protective layer is resistant to liquid metal attack, and wherein the protective layer includes an oxide of an element present in the alloy. A method of forming a protective layer on a surface of the alloy casting is also provided. The method includes disposing the alloy in a mold, and oxidizing an element of the alloy to form a protective layer on the surface of the casting.

Abstract: A system and method for directionally casting an elongated device are provided. The method includes orienting a mold within a furnace such that a first portion of the mold points downward. The first portion of the mold defines a space within the mold used to form a first end of the device. The first end of the device, when formed, has a greater mass than a second end of the device. The method also includes filling the mold with molten metal and lowering the mold out of the furnace into a liquid metal bath to immerse the first portion of the mold in the liquid metal bath. The method includes concurrently lowering the mold and the liquid metal bath to cool the molten metal.

Abstract: A system and method for directionally casting an elongated device are provided. The method includes orienting a mold within a furnace such that a first portion of the mold points downward. The first portion of the mold defines a space within the mold used to form a first end of the device. The first end of the device, when formed, has a greater mass than a second end of the device. The method also includes filling the mold with molten metal and lowering the mold out of the furnace into a liquid metal bath to immerse the first portion of the mold in the liquid metal bath. The method includes concurrently lowering the mold and the liquid metal bath to cool the molten metal.

Abstract: Methods for casting a metallic material to form a component are described. The component can be a superalloy-containing turbine part, for example. The general method includes the step of pouring the metallic material, in molten form, into an investment mold; and then rapidly immersing the entire investment mold into a bath that contains a low-melting liquid coolant metal, so as to achieve substantially uniform, multi-directional heat transfer out of the molten material. The molten material that solidifies to form the component is characterized by a fine-grained, equiaxed grain structure. Related embodiments include the use of two ingots that constitute the superalloy material. One ingot includes the oxygen-reactive elements, and is prepared by a vacuum-melting technique. The other ingot includes the remainder of the elements, and can be prepared by a number of techniques, such as air-melting processes.

Abstract: A system and method for directionally casting an elongated device are provided. The method includes orienting a mold within a furnace such that a first portion of the mold points downward. The first portion of the mold defines a space within the mold used to form a first end of the device. The first end of the device, when formed, has a greater mass than a second end of the device. The method also includes filling the mold with molten metal and lowering the mold out of the furnace into a liquid metal bath to immerse the first portion of the mold in the liquid metal bath. The method includes concurrently lowering the mold and the liquid metal bath to cool the molten metal.

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 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: Shell molds and processes for making the shell molds that exhibit high emissivity in the red and infrared regions. In this manner, thermal resistance within a gap formed between solidifying cast metal and the interior mold surface is decreased. In one embodiment, the facecoat region is formed from a slurry composition comprising an aluminum oxide, a green chromium oxide and a silicon dioxide. In another embodiment, the facecoat region is formed from a slurry composition including zirconium silicate and silica with stucco layer of alumina is included.

Abstract: Shell molds and processes for making the shell molds that exhibit high emissivity in the red and infrared regions. In this manner, thermal resistance within a gap formed between solidifying cast metal and the interior mold surface is decreased. In one embodiment, the facecoat region is formed from a slurry composition comprising an aluminum oxide, a green chromium oxide and a silicon dioxide. In another embodiment, the facecoat region is formed from a slurry composition including zirconium silicate and silica with stucco layer of alumina is included.

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: Shell molds and processes for making the shell molds that exhibit high emissivity in the red and infrared regions. In this manner, thermal resistance within a gap formed between solidifying cast metal and the interior mold surface is decreased. In one embodiment, the facecoat region is formed from a slurry composition comprising an aluminum oxide, a green chromium oxide and a silicon dioxide. In another embodiment, the facecoat region is formed from a slurry composition including zirconium silicate and silica with stucco layer of alumina is included.

Abstract: An alloy casting having a protective layer disposed on a surface of the casting is provided. The protective layer is resistant to liquid metal attack, and wherein the protective layer includes an oxide of an element present in the alloy. A method of forming a protective layer on a surface of the alloy casting is also provided. The method includes disposing the alloy in a mold, and oxidizing an element of the alloy to form a protective layer on the surface of the casting.

Abstract: A shell mold for casting molten material to form an article is described. The mold includes a shell for containing the molten material, formed from at least one of yttrium silicates, zirconium silicates, hafnium silicates, and rare earth silicates. The mold also includes a facecoat disposed on an inner surface of the shell that contacts the molten material. The facecoat can be made from the materials described above. A method of casting a niobium-silicide article is also described, using the shell mold described herein. A method of making the ceramic shell mold is described as well, along with a slurry composition used in the manufacture of the shell mold.

Abstract: A method for forming a dispersion-strengthened material containing nanoparticles that are uniformly dispersed in a matrix phase. The method includes adding nanoparticles and a molten material to a container to form a pool within the container and rotating the container to create a convection vortex in the pool. The convection vortex is sufficient to cause the nanoparticles to be incorporated into the molten material so as to yield a molten composite material, and further causes the molten composite material to be ejected from the container. The molten composite material is then cooled to form a solid composite body comprising a uniform dispersion of the nanoparticles.

Abstract: A mold is provided for enabling casting of single crystal metallic articles including a part-defining cavity, a sorter passage positioned vertically beneath and in fluid communication with the part-defining cavity, and a seed cavity positioned vertically beneath and in fluid communication with the sorter passage. The sorter passage includes a shape suitable for encouraging a single crystal structure in solidifying molten metal. Additionally, a portion of the mold between the sorter passage and the part-defining cavity includes a notch for facilitating breakage of a cast article proximate the notch during thermal stress build-up, so as to prevent mold breakage or the inclusion of part defects.

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: 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 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.