Abstract: Caustic solutions are employed in an autoclave process to rapidly remove cores made of .beta.-Al.sub.2 O.sub.3 from directionally solidified eutectic alloy and superalloy materials.

Abstract: Titanium is employed as a masking material for the selective etching of a coating material of a polyimide-silicone copolymer disposed on selective surface areas of electronic devices.

Abstract: An optical coating is disposed on selected surface areas of a semiconductor element to enchance processing thereof by TGZM

Abstract: Caustic solutions are employed in an autoclave process to rapidly remove the cores made of Y.sub.2 O.sub.3 from directionally solidified eutectic alloy and superalloy materials.

Abstract: Investment casting molds embody an alumina-silica composition for at least the primary coatings which comprises a flour mixture consisting of at least two different sizes of fused alumina. The grain sizes range from approximately 240 mesh to approximately 400 mesh, U.S. Standard or Tyler screen series.

Abstract: A two step inertia welding process is employed to join the stem to the substrate of a disc thereby forming an anode assembly for a rotating X-ray anode tube. The abutting surfaces to be joined are rubbed together to heat the substrate to an elevated temperature, at which time the weld joint is formed by inertia welding.

Abstract: A composition for making shell investment molds for the casting and solidification of superalloys therein embodies preparing a primary slurry composition of a mixture of three different flour grain sizes of fused alumina and a silica binder. The flour grain sizes range from approximately 240 mesh to approximately 400 mesh, U.S. Standard or Tyler screen series.

Abstract: A weakly acid solution of either NH.sub.4 NO.sub.3, NH.sub.4 Cl, NH.sub.4 HSO.sub.4, CH.sub.3 COOH or equimolar CH.sub.3 COOH -- CH.sub.3 COONa is employed to remove cores of either Y.sub.2 O.sub.3 or Sm.sub.2 O.sub.3 from castings of advanced superalloy materials. A molten salt bath may be used thereafter to remove reaction products formed by the reaction of the materials of the core and the metal casting.

Abstract: A graphite disc assembly for a rotating x-ray tube embodying a graphite substrate and an anode target of either tungsten or tungsten rhenium joined thereto by a layer of rhodium, osmium, ruthenium, platinum, platinum-chromium, or palladium.

Abstract: An inertia welding process is employed to join the stem to the substrate of a disc thereby forming an anode assembly for a rotating x-ray anode tube.

Abstract: An improved method of initiating the moving of a molten zone of an aluminum rich semiconductor material through a solid body of the same semiconductor material to form a planar region embodies alloying the aluminum metal to the semiconductor material of the surface of the body in contact therewith at a temperature of from 577.degree. to 660.degree. C. The alloying process enables one to migrate two or more intersecting "wires" simultaneously, as well as three "wires" intersecting at a common point of origin, through the body.

Abstract: Mixed oxide compounds La.sub.2 O.sub.3 . 11Al.sub.2 O.sub.3, NdAlO.sub.3 and nonstoichiometric MgAl.sub.2 O.sub.3 are suitable for making cores and molds for casting advanced superalloy materials such as NiTaC-13.

Abstract: An alumina core for investment casting directionally solidified eutectic and superalloy materials consists of a central portion which has porosity which is continuous throughout. The material of the central portion has a micro-structure which is characteristic of alumina grains which have undergone vapor phase transport action. An outer layer of alumina encompasses the central portion and in integral therewith and contains porosity which is discontinuous.

Abstract: A semiconductor body heater is provided with a planar array of radiant heating elements spaced from a reflector. In the preferred embodiment, each radiant heating element comprises a tungsten filament quartz lamp. Each lamp is removable and replaceable without disengaging any other lamp. The reflector is cooled by flows of gas and liquid coolant therethrough. Flows of gas between the planar array of lamps and the reflector and between the reflector and a cover member also cool the apparatus. Various diffusers for substantially eliminating temperature nonuniformities over an area illumined by the planar array of lamps are also disclosed. The semiconductor body heater of the present invention is particularly well suited for use in a temperature gradient zone melting process.

Abstract: A ceramic suitable for use in the casting of advanced superalloy materials has a structure including a predetermined porosity content and a material microstructure characterized by a high density of microcracks.

Abstract: An apparatus for imparting combined centro-symmetric and noncentro-symmetric rotation to semiconductor bodies comprises a liquid-cooled sun gear, a stationary liquid-cooled ring gear coaxial with and radially spaced outwardly from the sun gear, and at least one planet gear disposed between and driven in engagement with the sun and ring gears. Means are provided for supporting a semiconductor body on each of the planet gears while minimizing the conduction of heat from the semiconductor body to the planet gear. Means are also provided for guiding a semiconductor body onto the supporting means and centering the semiconductor body on the planet gear. Thermal distortion of the apparatus is minimized when heated to extreme temperatures making the apparatus ideally suited for processing the semiconductor bodies with heat as in processing by temperature gradient zone melting.

Abstract: The crushability of a ceramic article suitable for use in the casting and directional solidification of advanced superalloy materials is enhanced by utilizing a two-phase mixture of material and inducing microcracks in the material. The crushability is further enhanced by forming the article to include a predetermined porosity content.

Abstract: Cores made of either Y.sub.2 O.sub.3, Y.sub.3 Al.sub.5 O.sub.12, LaAlO.sub.3, MgAl.sub.2 O.sub.4 or Al.sub.2 O.sub.3 are removed from castings of advanced superalloy materials by immersion in a molten salt bath of either Li.sub.3 AlF.sub.6 or a mixture of CaF.sub.2 -- NaF.

Abstract: An anisotropic resistor for electrical feed throughs embodies a body of semiconductor material having at least one channel region of recrystallized material of the body formed therein. The channel region extends entirely through, and terminates in two major opposed surfaces of, the body. The at least one region is formed by a temperature gradient zone melting process, has a substantially uniform level of resistivity throughout the region and is electrically conductive.

Abstract: The geometric configuration of a molten zone migrating through a solid body of semiconductor material during thermal gradient zone melting is maintained by noncentro-symmetric rotation of the solid body about an axis displaced therefrom, by centro-symmetric rotation of the solid body, by translation of the solid body, by a combination of centro-symmetric rotation and translation of the solid body or by a combination of noncentro-symmetric rotation and translation of the solid body while being heated by a suitable heat source.