Abstract: A turbine system including a sealing component is presented. The sealing component is positioned in a gap between adjacent turbine components of the turbine system. The sealing component includes a metallic shim including a high-temperature-resistant alloy in a single crystal form. A turbine shroud assembly including the sealing component is also presented.

Abstract: Various embodiments include a gas turbine seal and methods of forming such seal. The method of forming the seal includes forming a freestanding ceramic seal for sealing in a gas turbine by applying a ceramic material on a substrate to form a ceramic layer, removing the substrate from the ceramic layer and finishing the ceramic layer to define the freestanding ceramic seal. The method includes depositing particles of the ceramic material in one of a molten or vapor state on a surface of the substrate and quenching the ceramic material to form the ceramic layer. The ceramic material comprises yttria-stabilized zirconia having a t? tetragonal structure. A gas turbine including the freestanding ceramic seal is additionally disclosed.

Abstract: A coated seal slot system for turbomachinery includes a first turbine component comprising a first groove having at least one first coating attached to at least a portion of the first groove of the first turbine component, a second turbine component comprising a second groove having at least one second coating attached to at least a portion of the second groove of the second turbine component. The first and the second turbine components are disposable adjacent to each other with the first groove having the first coating and the second groove having the second coating together forming a coated seal slot extending across a gap between the first turbine component and the second turbine component. A seal is disposable in the coated seal slot and extendable across the gap between the first and the second turbine components and engageable with the first coating and the second coating to inhibit leakage of gas through the gap.

Abstract: A turbine system including a sealing component is presented. The sealing component is positioned in a gap between adjacent turbine components of the turbine system. The sealing component includes a metallic shim including a high-temperature-resistant alloy in a single crystal form. A turbine shroud assembly including the sealing component is also presented.

Abstract: A turbine system including a sealing component is presented. The sealing component includes a ceramic material. The ceramic material includes grains having an average grain size of less than 10 microns. A turbine shroud assembly including the sealing component is also presented.

Abstract: Crucible compositions and methods of using the crucible compositions to melt titanium and titanium alloys. More specifically, crucible compositions having extrinsic facecoats comprising a rare earth oxide that are effective for melting titanium and titanium alloys for use in casting titanium-containing articles. Further embodiments are titanium-containing articles made from the titanium and titanium alloys melted in the crucible compositions. Another embodiment is a crucible curing device and methods of use thereof.

Abstract: The disclosure relates generally to mold compositions and methods of molding and the articles so molded. More specifically, the disclosure relates to mold compositions, intrinsic facecoat compositions, and methods for casting titanium-containing articles, and the titanium-containing articles so molded, where the mold comprises calcium hexaluminate.

Abstract: A coated seal slot system for turbomachinery includes a first turbine component comprising a first groove having at least one first coating attached to at least a portion of the first groove of the first turbine component, a second turbine component comprising a second groove having at least one second coating attached to at least a portion of the second groove of the second turbine component. The first and the second turbine components are disposable adjacent to each other with the first groove having the first coating and the second groove having the second coating together forming a coated seal slot extending across a gap between the first turbine component and the second turbine component. A seal is disposable in the coated seal slot and extendable across the gap between the first and the second turbine components and engageable with the first coating and the second coating to inhibit leakage of gas through the gap.

Abstract: Crucible compositions and methods of using the crucible compositions to melt titanium and titanium alloys. More specifically, crucible compositions having extrinsic facecoats comprising a rare earth oxide that are effective for melting titanium and titanium alloys for use in casting titanium-containing articles. Further embodiments are titanium-containing articles made from the titanium and titanium alloys melted in the crucible compositions. Another embodiment is a crucible curing device and methods of use thereof.

Abstract: Crucible compositions and methods of using the crucible compositions to melt titanium and titanium alloys. More specifically, crucible compositions having extrinsic facecoats comprising a rare earth oxide that are effective for melting titanium and titanium alloys for use in casting titanium-containing articles. Further embodiments are titanium-containing articles made from the titanium and titanium alloys melted in the crucible compositions. Another embodiment is a crucible curing device and methods of use thereof.

Abstract: A mixing device having a mixing container and has a single-shaft agitator that extends into the mixing container. At the end of the drive shaft, a rotor body is arranged slightly above the bottom of the mixing container. The rotor body comprises a plurality of mixing blades, wherein the blades are, in one example, star-shaped and fixed in position to each other. A first end of the drive shaft is coupled to a motor and a second end of the drive shaft is configured to extend into the mixing vessel, wherein the blades are attached onto the second end of the drive shaft. The blades in one example include at least two coincidental knife-edged blades such that at least one of the knife-edged blades is facing upward. The mixing device in one example is used to mix calcium aluminate-containing slurries.

Abstract: The disclosure relates generally to mold compositions and methods of molding and the articles so molded. More specifically, the disclosure relates to mold compositions, intrinsic facecoat compositions, and methods for casting titanium-containing articles, and the titanium-containing articles so molded, where the mold comprises calcium hexaluminate.

Abstract: Crucible compositions and methods of using the crucible compositions to melt titanium and titanium alloys. More specifically, crucible compositions having extrinsic facecoats comprising a rare earth oxide that are effective for melting titanium and titanium alloys for use in casting titanium-containing articles. Further embodiments are titanium-containing articles made from the titanium and titanium alloys melted in the crucible compositions. Another embodiment is a crucible curing device and methods of use thereof.

Abstract: A rare earth-based core for use in the casting of a reactive metal is described. The core contains a ceramic composition which includes at least about 10% by weight of monoclinic rare earth aluminate (RE4Al2O9), wherein RE represents at least one rare earth element; and at least about 10% by weight of at least one free rare earth oxide. The ceramic phase of the composition may include a microstructure which comprises a multitude of substantially spherical pores which are formed as a result of the removal of aluminum metal from the core composition during a heat treatment step. Additional embodiments relate to a method for the fabrication of a ceramic core, employing a rare earth oxide, aluminum metal, and a binder. Methods for removing cores from a cast part are also described.

Abstract: A rare earth-based core for use in the casting of a reactive metal is described. The core contains a ceramic composition which includes at least about 10% by weight of monoclinic rare earth aluminate (RE4Al2O9), wherein RE represents at least one rare earth element; and at least about 10% by weight of at least one free rare earth oxide. The ceramic phase of the composition may include a microstructure which comprises a multitude of substantially spherical pores which are formed as a result of the removal of aluminum metal from the core composition during a heat treatment step. Additional embodiments relate to a method for the fabrication of a ceramic core, employing a rare earth oxide, aluminum metal, and a binder. Methods for removing cores from a cast part are also described.

Abstract: Compositions suitable for use as cores and shell molds for casting of reactive metal alloys, and casting processes for producing components from such alloys. The composition contains a sintered particulate material of hafnia and at least one additional metal oxide in amounts to yield a ceramic composition containing up to 70 molar percent of hafnia, wherein the additional metal oxide is a rare-earth oxide, the sintered particulate material contains first and second phases, the first phase is the rare-earth oxide and hafnia in solid solution, the second phase is a compound of the rare-earth oxide and hafnia, and the second phase is less reactive with the reactive metal alloy than the first phase.

Abstract: A rare earth-based core for use in the casting of a reactive metal is described. The core contains a ceramic composition which includes at least about 10% by weight of monoclinic rare earth aluminate (RE4Al2O9), wherein RE represents at least one rare earth element; and at least about 10% by weight of at least one free rare earth oxide. The ceramic phase of the composition may include a microstructure which comprises a multitude of substantially spherical pores which are formed as a result of the removal of aluminum metal from the core composition during a heat treatment step. Additional embodiments relate to a method for the fabrication of a ceramic core, employing a rare earth oxide, aluminum metal, and a binder. Methods for removing cores from a cast part are also described.

Abstract: Compositions suitable for use as cores and shell molds for casting of reactive metal alloys, and casting processes for producing components from such alloys. The composition contains a sintered particulate material of hafnia and at least one additional metal oxide in amounts to yield a ceramic composition containing up to 70 molar percent of hafnia, wherein the additional metal oxide is a rare-earth oxide, the sintered particulate material contains first and second phases, the first phase is the rare-earth oxide and hafnia in solid solution, the second phase is a compound of the rare-earth oxide and hafnia, and the second phase is less reactive with the reactive metal alloy than the first phase.

Abstract: A rare earth-based core for use in the casting of a reactive metal is described. The core contains a ceramic composition which includes at least about 10% by weight of monoclinic rare earth aluminate (RE4Al2O9), wherein RE represents at least one rare earth element; and at least about 10% by weight of at least one free rare earth oxide. The ceramic phase of the composition may include a microstructure which comprises a multitude of substantially spherical pores which are formed as a result of the removal of aluminum metal from the core composition during a heat treatment step. Additional embodiments relate to a method for the fabrication of a ceramic core, employing a rare earth oxide, aluminum metal, and a binder. Methods for removing cores from a cast part are also described.

Abstract: A method of removing an yttria-based core from a niobium-based part is described. In the method, the core is treated with an effective amount of a leaching composition. The leaching composition is based on nitric acid, or a combination of nitric acid and phosphoric acid. The core material is effectively removed from the niobium-based part, and the process of removing the core does not detrimentally affect the quality of the part. Related casting techniques for various niobium-based parts are also described.