Abstract: Sintered silicon nitride products comprising predominantly ?-silicon nitride grains in combination with from about 0.1 to 30 mole % silicon carbide, and grain boundary secondary phases of scandium oxide and scandium disilicate. Such products have high fracture toughness, resistance to recession, and resistance to oxidation at temperatures of at least 1500° C. Methods for preparing sintered silicon nitride products are also disclosed.

Abstract: A turbomachinery component includes a substrate having a surface, the surface consisting essentially of at least one composite of at least one metal and at least one compound having the chemical formula Mn+1AXn, wherein M is at least one early transition metal selected from groups IIIB, IVB, VB, and VIB, A is at least one element selected from groups IIIA, IVA, VA, VIA, and VIIA, X is one or both of carbon and nitrogen, and n is an integer between 1 and 3. The component is made by compressing a powdered material to form a substrate that consists essentially of the composite and sintering the substrate, or by coating a substrate with the composite.

Abstract: A method and superalloy component for depositing a layer of material onto gas turbine engine components by atomic layer deposition. A superalloy component may have a ceramic thermal barrier coating on at least a portion of its surface, comprising a superalloy substrate and a bonding coat; and aluminum oxide (Al2O3) layer may be deposited on top of an yttria-stabilized zirconia layer and form a bonding coat by atomic layer deposition. The yttria-stabilized zirconia layer may have a plurality of micron sized gaps extending from the top surface of the ceramic coating towards the substrate and defining a plurality of columns of the yttria-stabilized zirconia layer. Also, atomic layer deposition may be used to lay an aluminum oxide (Al2O3) layer over a tantalum oxide (Ta2O5) layer on a silicon-based substrate.

Abstract: A protective barrier coating system including a diffusion barrier coating and an oxidation barrier coating and method for use in protecting silicon-based ceramic turbine engine components. A complete barrier coating system includes a thermal barrier coating of stabilized zirconia and an environmental barrier coating of an alloyed tantalum oxide. The oxidation barrier coating includes a layer of metallic silicates formed on a substrate of silicon nitride or silicon carbide to be protected. The oxidation barrier coating can include silicates of scandium, ytterbia or yttrium. The oxidation barrier coating may also include an inner layer of Si2ON2 between the diffusion barrier and the metallic silicate layer. The oxidation barrier coating can be applied to the substrate by spraying, slurry dipping and sintering, by a sol-gel process followed by sintering, by plasma spray, or by electron beam-physical vapor deposition.

Abstract: A component comprises a silicon-based substrate; and a protective coating for the substrate. The protective coating includes tantalum oxide (Ta2O5) and an additive for suppressing transformation from beta Ta2O5 to alpha Ta2O5.

Abstract: A component comprising a silicon-based substrate and a braze-based protective coating disposed on the silicon-based substrate. The braze-based coating comprises a brazed layer, wherein the brazed layer comprises at least one intermetallic compound. A scale layer may be formed on the brazed layer. An environmental barrier coating may be disposed directly on the brazed layer or directly on the scale layer. A thermal barrier coating may be disposed on the environmental barrier coating. Methods for making a Si-based component having a braze-based protective coating are also disclosed.

Abstract: A component comprises a silicon-based substrate; and a protective coating for the substrate. The protective coating includes tantalum oxide (Ta2O5) and an additive for suppressing transformation from beta Ta2O5 to alpha Ta2O5.

Abstract: A component comprising a silicon-based substrate and a diffusion barrier coating disposed on the silicon-based substrate. The diffusion barrier coating comprises an isolation layer disposed directly on the silicon-based substrate and at least one oxygen barrier layer disposed on the isolation layer. The oxygen barrier layer prevents the diffusion of oxygen therethrough, and prevents excessive oxidation of the silicon-based substrate. The isolation layer(s) prevent contaminants and impurities from reacting with the oxygen barrier layer. An environmental barrier coating may be disposed on the diffusion barrier coating, and a thermal barrier coating may be disposed on the environmental barrier coating. Methods for making a component having a diffusion barrier coating are also disclosed.

Abstract: Sintered silicon nitride products comprising predominantly ?-silicon nitride grains in combination with from about 0.1 to 30 mole % silicon carbide, and grain boundary secondary phases of scandium oxide and scandium disilicate. Such products have high fracture toughness, resistance to recession, and resistance to oxidation at temperatures of at least 1500° C. Methods for preparing sintered silicon nitride products are also disclosed.

Abstract: An environmentally and thermally protected component comprising a silicon-based ceramic or composite substrate and an environmental and thermal barrier coating disposed on the substrate. The environmental and thermal barrier coating comprises at least about 50 mole % AlTaO4. The composition of the environmental and thermal barrier coating may be adapted to provide excellent CTE (coefficient of thermal expansion) match with a substrate, such as a SiC-based ceramic or composite. Coating compositions of the invention have a stable crystalline structure at a temperature up to at least about 1550° C. Methods for preparing an environmentally and thermally protected component are also disclosed.

Abstract: A component comprises a silicon-based substrate; and a protective coating for the substrate. The protective coating includes tantalum oxide (Ta2O5) and an additive for suppressing transformation from beta Ta2O5 to alpha Ta2O5.

Abstract: A turbomachine component includes a silicon nitride substrate and a protective coating on the substrate. The protective coating includes a porous silicon nitride matrix and a noble metal infiltrated in the porous silicon nitride matrix.

Abstract: An apparatus and method for issue grouping of instructions in a VLIW processor is disclosed. There can be one, two, or three issue groups (but no greater than three issue groups) in each VLIW packet. In one embodiment, a template in the VLIW packet comprises two issue group end markers where each issue group end marker comprises three bits. The three bits in the first issue group end marker identifies the instruction which is the last instruction in the first issue group. Likewise, the three bits in the second issue group end marker identifies the instruction which is the last instruction in the second issue group. Any instructions in the VLIW packet falling outside the two expressly defined first and second issue groups are placed in a third issue group. As such, three issue groups can be identified by use of the two issue group end markers. In one embodiment, the template of the VLIW packet includes a chaining bit.

Abstract: A turbomachine component includes a silicon nitride substrate and a multi-layer coating bonded to the substrate. The coating includes an interlayer of porous fibrous silicon nitride having a density of between 85-98%. The coating also includes an outer layer formed of an oxide compound, preferably tantalum oxide, that is applied by Electron Beam-Physical Vapor Deposition. The combination of the silicon nitride interlayer and tantalum oxide outer layer serves to protect the substrate from the adverse affects of oxidation, impact by foreign objects and extreme operating temperatures.

Abstract: An apparatus and method for issue grouping of instructions in a VLIW processor is disclosed. There can be one, two, or three issue groups (but no greater than three issue groups) in each VLIW packet. In one embodiment, a template in the VLIW packet comprises two issue group end markers where each issue group end marker comprises three bits. The three bits in the first issue group end marker identifies the instruction which is the last instruction in the first issue group. Likewise, the three bits in the second issue group end marker identifies the instruction which is the last instruction in the second issue group. Any instructions in the VLIW packet falling outside the two expressly defined first and second issue groups are placed in a third issue group. As such, three issue groups can be identified by use of the two issue group end markers. In one embodiment, the template of the VLIW packet includes a chaining bit.

Abstract: A component comprises a silicon-based substrate; and a protective coating for the substrate. The protective coating includes tantalum oxide (Ta2O5) and an additive for suppressing transformation from beta Ta2O5 to alpha Ta2O5.

Abstract: An apparatus and method for issue grouping of instructions in a VLIW processor is disclosed. There can be one, two, or three issue groups (but no greater than three issue groups) in each VLIW packet. In one embodiment, a template in the VLIW packet comprises two issue group end markers where each issue group end marker comprises three bits. The three bits in the first issue group end marker identifies the instruction which is the last instruction in the first issue group. Likewise, the three bits in the second issue group end marker identifies the instruction which is the last instruction in the second issue group. Any instructions in the VLIW packet falling outside the two expressly defined first and second issue groups are placed in a third issue group. As such, three issue groups can be identified by use of the two issue group end markers. In one embodiment, the template of the VLIW packet includes a chaining bit.

Abstract: A turbomachine component includes a silicon nitride substrate and a multi-layer coating bonded to the substrate. The coating includes an interlayer of porous fibrous silicon nitride having a density of between 85-98%. The coating also includes an outer layer formed of an oxide compound, preferably tantalum oxide, that is applied by Electron Beam-Physical Vapor Deposition. The combination of the silicon nitride interlayer and tantalum oxide outer layer serves to protect the substrate from the adverse affects of oxidation, impact by foreign objects and extreme operating temperatures.

Abstract: A method for forming a ceramic part with an internal structure includes aqueous slip-casting and a polystyrene foam insert. An aqueous slurry is poured over the insert to form a green body. The insert is shaped to produce the desired internal structure upon being encased by the slurry. The insert is then removed from the green body by dissolving it in trichloroethylene. Because the polystyrene foam does not expand when exposed to trichloroethylene and rapidly dissolves, build up of shrinkage stress in the green body is avoided. The green body is then sintered to produce the ceramic part with an internal structure.

Abstract: A coating of whisker shaped beta silicon nitride grains are formed upon a silicon nitride substrate by sintering over a period of several hours, and the resulting product has a porous reaction bond coating strongly adhered to the silicon nitride substrate.