Abstract: This invention relates to a disk substrate consisting essentially of zirconia partially stabilized by a rare earth oxide, the disk substrate having a thickness of no more than 0.635 mm, a diameter of at least 10 mm, and a mean pore size of no more than 0.1 um.

Abstract: This invention relates to a torch comprising:a) a nozzle having a bore extending therethrough, the bore comprising a first end portion, a second end portion, and an arcuate middle portion defining an arcuate tube surface,b) means for providing a flame flowing from the first end portion of the bore towards the second end portion of the bore, so that the flame impinges upon the arcuate tube surface,wherein the arcuate tube surface comprises silicon carbide.

Abstract: A modular igniter system which preferably provides either direct electrical connection between the metallized ends of the hot surface igniter and the socket contact, or indirect electrical connection by a short lead wire held in place on the hot surface element by an active metal braze.

Abstract: A ceramic igniter comprisesa pair of conductive ends,a hot zone disposed between the conductive ends, the hot zone having a density of at least about 95% of theoretical density and a composition comprising:(a) between about 50 and about 80 vol % of an electrically insulating material selected from the group consisting of aluminum nitride, boron nitride, silicon nitride, and mixtures thereof.(b) between about 10 and about 45 vol % of a semiconductive material selected from the group consisting of silicon carbide and boron carbide, and(c) between about 5 and about 25 vol % of a metallic conductor selected from the group consisting of molybdenum disilicide, tungsten disilicide, titanium nitride, and mixtures thereof, anda support upon which the hot zone is disposed, wherein at least a portion of the hot zone has a thickness of no more than 0.019".

Abstract: Sol-gel alumina that is dried but unfired can be explosively comminuted by feeding the dried gel into a furnace held at temperatures above those at which vaporizable materials are eliminated from the particles of gel. At suitably elevated temperatures the firing is sufficient to form fully densified alpha alumina particles of a size suitable for direct use as abrasive grits.

Abstract: A ceramic igniter comprising:a) a pair of electrically conductive portions, each portion having a first end,b) a hot zone disposed between and in electrical connection with each of the first ends of the electrically conductive portions, the hot zone having an electrical path length of less than 0.5 cm, andc) an electrically non-conductive heat sink material contacting the hot zone.

Abstract: A mandrel for use in a diamond deposition process for generating free standing diamond films has a segmented surface forming a plurality of surfaces for deposition of diamond. The segmented surface is formed of a plurality of mesa segments on a common supporting base surfaces for the mesas. The mesa segments are preferably removably attached to the common base by any suitable means such as by bolts through the mandrel substrate which extend into the mesa segments. The mesa segments may vary in shape, size, and number, thus permitting different shaped diamond films to be made simultaneously from the same run if desired. The provided arrangement increases yield by reducing losses due to premature lifting of the diamond film during deposition, due to violent lifting after deposition upon cooling of the mandrel, and due to cracking.

Abstract: This invention relates to a Hall-Heroult cell for aluminum production comprising a cryolite-resistant liner comprising:i) between 75 weight percent wt % and 95 wt % alumina-silica refractory grain, andii) between 1 wt % and 10 wt % of a sealant selected from the group consisting of feldspar and nepheline.

Abstract: Sol-gel alumina that is dried but unfired can be explosively comminuted by feeding the dried gel into a furnace held at temperatures above those at which vaporizable materials are eliminated from the particles of gel. At suitably elevated temperatures the firing is sufficient to form fully densified alpha alumina particles of a size suitable for direct use as abrasive grits.

Abstract: A ceramic igniter comprising: a) a lead wire, b) a ceramic substrate, and c) a braze pad having a thickness of less than about 150 microns, wherein the lead wire and ceramic substrate are placed in electrical connection by the braze pad.

Abstract: An IC package includes a high thermal conductivity insulating material substrate, such as polycrystalline diamond or diamond-coated silicon carbide or molybdenum, on which the IC is mounted for thermal management. The electrical lead pins of the package are electrically connected to the IC and thermally connected to the substrate. The thermal connection can be by bonding the pins directly to the substrate.

Abstract: A method for depositing a substance, such as diamond, on a surface of a substrate with temperature control, which comprises the steps of providing a cooling block having a surface that is cooled by heat exchange; supporting said substrate from said cooling block so that the bottom surface of said substrate is spaced from said cooling block surface by a gap, the size of said gap being in the range of 0.01 cm to 0.30 cm; providing a gas in said gap; and depositing said substance on the top surface of said substrate, whereby heat, resulting from said depositing of said substance, flows by conduction across said gap from said substrate to said cooling block.

Abstract: A synthetic diamond film structure, comprising a generally planar free standing layered diamond structure having a surface area of at least 1000 square millimeters, having the following layers: a first layer having a first thicknesss and a relatively low intrinsic stress; and second layer having a second thickness and a relatively high intrinsic stress; the first thickness being sufficiently thick to prevent the diamond structure from bowing by more than a given distance.

Abstract: A radiation detection system and method for scanning an object for ionizing radiation are generally characterized by at least one radiation detector which provides an output related to the level of ionizing radiation impinging thereon, a sensing device which evaluates and provides an output related to a shape characteristic of an object being scanned by the radiation detector, and a processor operatively connected to the radiation detector and sensing device for processing the outputs thereof. The output of the sensing device is used to compensate for variations in ambient background level arising from the sensed shape characteristic of the object. With such a system, the possibility of a geometry induced false alarm is minimized. In a preferred embodiment adapted for dynamic vehicle monitoring, the sensing device is a level detector operative to detect the level of the material in a truck or rail car passing by the radiation detector or detectors.

Abstract: A mandrel for use in an arc-jet spinning diamond deposition process for coating cutting tool inserts is disclosed. The mandrel has a plurality of cutouts or wells for receiving cutting tool inserts. The receiving wells are machined or otherwise provided to have the same contour as the cutting tool inserts that are placed in the wells. The receiving wells may all have an identical geometry, or different geometries. In one embodiment, the mandrel comprises a single element with the receiving wells machined into the upper surface of the mandrel. In another embodiment, the mandrel comprises a separate upper plate with the receiving wells cut through the plate to form a grid, and a lower base plate which is attached to the upper plate. An intermediate layer of a low melting metal foil may be placed between the grid and base plate to aid adhesion and to provide an interface of high thermal conductivity.

Abstract: At least the surface region of a cutting tool substrate made of tungsten carbide in a cobalt matrix is carburized to chemically passivate the cobalt prior to deposition of diamond film on it. The passivation improves adhesion by preventing reaction of the cobalt with the diamond in the course of the deposition process.

Abstract: Precision measuring instruments having highly parallel and wear-resistant contact members and a method for fabricating these contact areas are disclosed. The measuring instruments preferably include two contact members each having diamond coated ceramic substrates. The method for diamond coating the contact members of the measuring instruments includes, for each contact member, preparing a ceramic substrate to high tolerance so that it has two surfaces which are parallel within 0.25 microns, diamond coating one surface of the substrate by any one of several chemical vapor deposition (CVD) techniques, and metalizing the other surface of the substrate for affixing it to the contact member of the measuring instrument. The metalized surface of the substrate is preferably affixed to the contact members of the measuring instrument by brazing, gluing or welding. Preferred embodiments of the measuring instruments with diamond coated contact areas include calipers and micrometers.

Abstract: A process is provided that permits the rapid quenching of molten ceramics by passing a flow of the molten ceramic into a turbulent fluid flow such that the flow is broken up into particles which then solidify as they pass into and through a cyclone and are finally separated from the fluid flow and collected as dry particulate ceramic materials.

Abstract: A blade sharpener for a pocket knife is in the form of an appendage which can be removably secured to the knife handle and which carries a superabrasive layer sharpening surface, such as an electroplated diamond grit. The appendage may take the form of a pair of tweezers, such as those commonly found on Swiss army type knives, with the superabrasive layer being attached to its inside surfaces.

Abstract: The use of purified process materials in the production of a seeded sol-gel alumina abrasive results in an abrasive of superior properties.