Abstract: A method for forming an exterior surface of a high-temperature component, such as a blade or vane of a gas turbine engine. The method entails forming a shell by a powder metallurgy technique that yields an airfoil whose composition can be readily tailored for the particular service conditions of the component. The method generally entails providing a pair of inner and outer mold members that form a cavity therebetween. One or more powders and any desired reinforcement material are then placed in the cavity and then consolidated at an elevated temperature and pressure in a non-oxidizing atmosphere. Thereafter, at least the outer mold member is removed to expose the consolidated powder structure. By appropriately shaping the mold members to tailor the shape of the cavity, the consolidated powder structure has the desired shape for the exterior shell of a component, such that subsequent processing of the component does not require substantially altering the configuration of the exterior shell.

Abstract: A method for casting a turbine bucket with at least one surface cooling hole. The method comprises positioning at least one preformed spacer device on a core, where the preformed spacer device is formed of ceramic materials and comprises opposed end plates and at least one interconnecting crossover pin connecting the end plates; forming a layer of temporary material, such as wax, over the core and around the at least one preformed spacer device; forming a shell mold over the layer of temporary material to cover it, the core and the at least one preformed spacer device. The shell mold is maintained stably positioned and spaced from the core by the at least one preformed spacer device, which connects and maintains the shell mold and the core as a stable body. The wax is removed to form a casting space for the turbine bucket between the shell mold and the core and around the at least one preformed spacer device.

Abstract: A silicide-based composite toughened with a niobium-based metallic phase and further containing a silicon-modified chromium-based Laves-type phase to promote oxidation resistance. The silicide-based composite generally contains one or more silicide intermetallic phases, each of which is an M.sub.5 Si.sub.3 -type or an M.sub.3 Si-type phase where M is at least Nb+Ti+Hf. The niobium-based metallic phase contains at least niobium, titanium, hafnium, chromium, aluminum and silicon. The silicon-modified Laves-type phase is of the Cr.sub.2 M type where M is Nb+Ti+Hf. The silicide-based composite is formulated to contain greater than 25 volume percent of the niobium-based metallic phase, the balance being the silicide intermetallic phases and the silicon-modified Laves-type phase.

Abstract: An in-situ method for thermal desorption, extraction, and destruction of dense nonaqueous organic contaminants in fractured bedrock is accomplished through the use of thermal wells, a flameless oxidizer, and hot carbon adsorption chambers.

Abstract: A silicide-based composite toughened with a niobium-based metallic phase, and further containing a phase that significantly improves the oxidation resistance of the composite. The oxidation-resistant phase is a chromium-based Laves-type phase modified with silicon, which has been shown to greatly increase the oxidation resistance of silicide-based composites at temperatures of up to 1200 C. The oxidation-resistant silicide-based composite generally contains one or more silicide intermetallic phases, each of which is an M.sub.5 Si.sub.3 -type phase where M is Nb+Ti+Hf. The niobium-based metallic phase contains niobium, titanium, hafnium, chromium, aluminum and silicon. The silicon-modified Laves-type phase is of the Cr.sub.2 M type where M is Nb+Ti+Hf. A silicide-based composite contains, in atomic percent, about 12-25% titanium, about 6-12% hafnium, about 15-25% chromium, about 1-8% aluminum and about 12-20% silicon, with the balance essentially niobium.

Abstract: A plasma display comprises a face plate; at least one energy source; a first layer comprising pigmented phosphors; and a second layer comprising non-pigmented phosphors. The at least one energy source emits energy that is capable of exciting the non-pigmented phosphors of the second layer. Thus, the non-pigmented phosphors of the second layer emit energy comprising visible light. The first layer comprising the pigmented phosphors acts as a filter to filter the emissions from the non-pigmented phosphors of the first layer. Therefore, the plasma display has at least an increase in contrast of the energy emitted therefrom.

Abstract: A current limiting device has an electrically conductive composite material, an inhomogeneous distribution of resistance structure comprises a conducting filler, and at least two electrodes. At least one of the electrodes is a flexible electrode to maintain contact between the electrode and the composite material, regardless of the consumption of the composite material during a high current condition.

Abstract: A new method for forming a joint between a molybdenum-based alloy structure and a structure formed from a more ductile alloy is disclosed. The method involves the solid-state bonding of the two structures, which can be carried out by a variety of techniques, such as inertia-welding or explosive-welding. The molybdenum-based alloy may be a TZM-type material, while the more ductile alloy may be tantalum-based, niobium-based, or nickel-based, for example. This method is especially useful in the manufacture of x-ray devices, such as those which include rotary anode assemblies. As one illustration, the method can be used to provide a very strong joint between a target formed from a molybdenum alloy and an insert formed from a tantalum alloy. Related x-ray assemblies are also described.

Abstract: A steel comprises additives including rare earth elements, boron and at least one of rhenium, osmium, iridium, ruthenium, rhodium. The steel exhibits resistance to embrittlement, oxidation and creep. The steel also comprises balanced amounts of nickel and cobalt to minimize a ratio of nickel to cobalt, and optimize aging embrittlement resistance with as tempered toughness. The steel comprises, by weight percent: at least one of rhenium, osmium, iridium, ruthenium, rhodium (0.01 to 2.00); rare earth element (0.50 max.); boron (0.001-0.04); carbon (0.08-0.15); silicon (0.01-0.10); chromium (8.00-13.00); at least one of tungsten and molybdenum (0.01 to 2.00); at least one austenite stabilizer; such as nickel, copper, cobalt and manganese (0.001-6.00); vanadium (0.25-0.40); phosphorus (0.010 max.); sulfur (0.004 max.); nitrogen (0.060 max.); hydrogen (2 ppm max.); oxygen (50 ppm max.); aluminum (0.001-0.025); arsenic (0.0060 max.); antimony (0.0030 max.); tin (0.0050 max.); iron (balance).

Abstract: A method for forming integral extensions on the end of directionally oriented, superalloy articles, such as airfoil blading members or other components used in gas turbine or other turbine engines. An extension is formed directly on an article by dipping a portion or end of the article into a molten bath of a compatible alloy, followed by withdrawal of the end under controlled conditions sufficient to cause an integral extension to solidify on the article. A ceramic mold is utilized over the dipped end of the article with a mold cavity that generally defines the shape of the extension to be formed. The mold may be formed in situ, or preformed and attached to the subject article. Extensions formed by the method of this invention have a microstructure that is continuous and compatible with that of the article. Such microstructures may include epitaxial growth of the extension from the microstructure of the article.

Abstract: An infrared energy reflecting enamel composition comprises a ground coat of enamel on a substrate and embedded TiO.sub.2 particles in the ground coat of enamel. The infrared reflecting enamel composition has an infrared energy reflectivity value of at least 80%. A method for manufacturing the composition is also disclosed for embedding the TiO.sub.2 in the enamel.

Abstract: An opaque silica comprises silica and at least one second phase solid material. The at least one second phase solid material is essentially uniformly dispersed in the silica. A cut surface formed through the silica is free from surface defects since the at least one second phase solid material forms an opaque silica that is free from porosity.

Abstract: An infrared energy cooking and heating apparatus comprises an infrared layer or reflective coating, particularly on inner panels of ovens or other cooking devices. The coating is preferably an enamel and reflects the infrared energy to the food being cooked and heated. In particular, the infrared cooking apparatus are substantially faster than such processes in conventional ovens, and offer improvements in foodstuff cooking times. The enamel comprises metal oxide particles that enhance the infrared energy reflectivity of the enamel. Further, the metal oxide particles in the enamel can be formed in several ways so as to enhance the reflectivity.

Abstract: A sensor for sensing conditions on an object. The sensor comprises a first at least partially reflective surface layer disposed adjacent the object in close conforming relationship with a surface of the object, an intermediate layer, and a second at least partially reflective surface layer. The intermediate layer is disposed between the first at least partially reflective surface layer and the second at least partially reflective surface layer. The intermediate layer can be formed as a solid element, a combination of solid areas and spaces, and as an aerogel.

Abstract: A method for determining the effective level of catalyst for the preparation of a polycarbonate polymer by a transesterification reaction is disclosed. The method involves measurement of the leaving group by-product (usually phenol) produced in a test reaction between an aromatic dihydroxy compound and a carbonic acid diester, in the presence of a known amount of transesterification catalyst. The by-product production values can be compared with by-product reference values to calculate the effective level of catalyst. This data can be used to efficiently control catalytic activity in a production scale reaction for producing polycarbonate polymer.

Abstract: A current limiting system for a circuit limits current flow through the system. The current limiting system comprises at least one main switch comprising first and second main switch contacts and a contactor connecting the first and second main switch contacts; at least one current limiting device and at least one solid-state switch, which are mechanically unconnected to the main switch, and the at least one current limiting device and least one solid-state switch are arranged in series on a series side of the circuit; the at least one main switch is on a main switch side of the circuit arranged in parallel with the series side; a control that senses a predetermined condition of the circuit, and operably connected with the at least one solid state switch to open and it. Under normal operating conditions, most current flows through the at least one main switch side. When the predetermined condition causes the main switch to open, and the resistance increases in a main switch side.

Abstract: A method for making bisphenol salt as the result of the reaction between bisphenol and an alkali metal hydroxide. The method comprising steps to obtain the anhydrous alkali metal bisphenoxide salt within about a 0.2 mol % stoichiometry relationship between bisphenol and alkali metal hydroxide. A method for determining stoichiometry error of a sample comprises determining variables and applying the variables to an equation to determine stoichiometry.

Abstract: A superconductive article is made from interconnected superconductive, metallic tapes. The tapes are mechanically joined, and electrically interconnected by a plurality of superconductive interconnections that extend between the tapes. Articles of the invention may be formed from tapes comprising superconductive Nb.sub.3 Sn having Nb.sub.3 Sn interconnections.

Abstract: Nb-base alloys that include Ti, Hf, Cr, Al and Si as alloy constituents have a microstructure that includes a metallic solid solution phase and a mixture of intermetallic silicide phases. The metal silicide phases include an M.sub.3 Si silicide, where M comprises Nb, Ti or Hf, and an M.sub.5 (Si, Al).sub.3 silicide, where M comprises Nb, Ti or Hf. These alloys have mechanical properties such as low temperature fracture toughness, high temperature fracture strength, high temperature stress rupture strength and high temperature creep resistance, that meet or exceed those of certain Ni-base superalloys.

Abstract: Additions of a first alloy constituent of at least one element from the group consisting of Y, Sc, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu, or any combinations of them, and a second alloy constituent of at least one element from the group consisting of C, Si, Ge, Sn and Pb, or any combinations of them, to Ti-base alloys can be employed so as to result in an alloy containing an very fine, substantially homogeneous oxide dispersoid of the first constituent, and produce alloys having improved tensile properties, especially tensile elongation. The dispersoid results from the decomposition of an intermediate phase dispersoid comprising a compound of the first and second constituents which results from rapid solidification of the alloy from a melt. It is preferred that the second alloy constituent should be at a concentration sufficient to form the intermediate phase with all of the element or elements comprising the first alloy constituent.