Abstract: Diamond is deposited by chemical vapor deposition on two parallel substrates, by means of a plurality of filaments between said substrates. The substrates and filaments are in vertical configuration and the filaments are linear and spring-tensioned to compensate for thermal expansion and expansion caused by filament carburization. The apparatus includes at least one and preferably two temperature controlling means, usually heat sinks, to maintain substrate temperature in the range of 900.degree.-1000.degree. C., for optimum rate of diamond deposition.

Abstract: A plural substrate CVD apparatus for diamond crystal production utilizes spaced apart vertical, parallel, planar substrate panels with an electrical (direct current, D.C.) resistance filament heater therebetween. A hydrogen-hydrocarbon gas mixture flows between panels to come into contact with the heater and the panels to cause diamond crystal nucleation and growth on the substrate panels. The apparatus includes means for maintaining the spaced relationship of the heater from the substrate surfaces, comprising a rod member attached to one end of the heater and tensioned by a cable passing over a pulley member and attached to a weight.

Abstract: Diamond is deposited by chemical vapor deposition on two parallel substrates, by means of a plurality of filaments between the substrates. The substrates and filaments are in vertical configuration and the filaments are prestressed to curve in a single plane parallel to the substrates, to allow for thermal expansion and expansion caused by filament carburization. The apparatus includes at least one and preferably two heat sinks to maintain substrate temperatures in the range of 900.degree.-1000.degree. C., for optimum rate of diamond deposition.

Abstract: A smooth surface of a diamond or cubic boron nitride crystal is bombarded with ions sufficiently to penetrate the surface and impart an ion implanted region in the crystal in a predetermined pattern, the resulting crystal is charged electrostatically, and a powder is applied to the charged smooth surface producing a pattern thereon which is a delineation of the implanted region and can be used to identify or fingerprint the crystal.

Abstract: Compacts are provided in which one or more single crystal diamonds, having a largest dimension of at least one millimeter, are embedded in the polycrystalline matrix which may be made of diamond; cubic boron nitride (CNB); and silicon and silicon carbide bonded diamond, CBN, or mixtures of diamond and CBN. The single crystal diamond is from 10-90 volume percent of the compact.The compacts (except for the silicon and silicon carbide variety) are made by high pressure-high temperature processing generally in the range of 50 Kbar at 1300.degree. C. to 85 Kbar at 1750.degree. C.They have applications in several fields, for example, wire drawing die blands, cutting tool blanks, and anvils for high pressure apparatus.

Abstract: A mass of diamond crystals in contact with a mass of eutectiferous silicon-rich alloy and a silicon carbide ceramic substrate are disposed in a container and placed within a pressure transmitting powder medium. Pressure is applied to the powder medium resulting in substantially isostatic pressure being applied to the container and its contents sufficient to dimensionally stabilize the container and its contents. The resulting shaped substantially isostatic system of powder-enveloped container is hot-pressed whereby fluid eutectiferous silicon-rich alloy is produced and infiltrated through the interstices between the diamond crystals and contacts the contacting face of the silicon carbide substrate sufficiently producing, upon cooling, an adherently bonded integral composite.

Abstract: A mass of diamond crystals in contact with a mass of eutectiferous silicon-rich alloy and a silicon nitride ceramic substrate are disposed in a container and placed within a pressure transmitting powder medium. Pressure is applied to the powder medium resulting in substantially isostatic pressure being applied to the container and its contents sufficient to dimensionally stabilize the container and its contents. The resulting shaped substantially isostatic system of powder-enveloped container is hot-pressed whereby fluid eutectiferous silicon-rich alloy is produced and infiltrated through the interstices between the diamond crystals and contacts the contacting face of the silicon nitride substrate sufficiently producing, upon cooling, an adherently bonded integral composite.

Abstract: An adherently bonded polycrystalline diamond body is produced by forming a charge composed of a mass of diamond crystals in contact with a mass of eutectiferous silicon-rich alloy wherein the alloy is in contact or in association with hexagonal boron nitride, confining such charge within a reaction chamber, subjecting the confined charge to a pressure of at least 25 kilobars, heating the pressure-maintained charge to a temperature sufficient to melt the alloy and at which no significant graphitization of the diamond occurs whereby the alloy infiltrates through the interstices between the diamond crystals producing said body.

Abstract: A cavity of predetermined size is formed in a compressed pressure transmitting powder medium, a mass of diamond crystals in contact with a mass of elemental silicon are disposed within the cavity and additional pressure transmitting powder is placed over the cavity and its contents producing a powder-enveloped cavity. Pressure is applied to the powder medium resulting in substantially isostatic pressure being applied to the cavity therein and its contents sufficient to dimensionally stabilize the cavity and its contents. The resulting shaped substantially isostatic system of powder-enveloped diamond and silicon is hot-pressed to liquefy and infiltrate the silicon through the interstices between the diamond crystals producing, upon cooling, an adherently bonded integral body.

Abstract: Cores made of alumina-based ceramics, such as .beta.-alumina materials, are substantially non-reactive with directionally solidified eutectic and superalloy materials, do not cause hot cracking of the same, and are easily leachable from the cast metal.

Abstract: A mass of diamond crystals contacting a mass of elemental silicon are confined within a pressure-transmitting medium. The resulting charge assembly is subjected to a pressure of at least 25 kilobars causing application of isostatic pressure to the contacting masses which dimensionally stabilizes them and increases the density of the mass of diamond crystals. The resulting pressure-maintained charge assembly is heated to a temperature sufficient to melt the silicon and at which no significant graphitization of the diamond occurs whereby the silicon is infiltrated through the interstices between the diamond crystals producing, upon cooling, an adherently bonded integral body.

Abstract: A diamond or cubic boron nitride crystal containing growth discontinuities resulting from changes in the environment of the growing crystal and having at least one smooth outside surface which intersects the growth discontinuities is charged electrostatically, a fine powder is applied to the charged smooth surface and the applied powder produces a pattern on the charged surface which is a delineation of the intersected growth discontinuities.

Abstract: A mass of diamond crystals in contact with a mass of eutectiferous silicon-rich alloy are disposed in a container and placed within a pressure transmitting powder medium. Pressure is applied to the powder medium resulting in substantially isostatic pressure being applied to the container and its contents sufficient to dimensionally stabilize the container and its contents. The resulting shaped substantially isostatic system of powder-enveloped container is hot-pressed whereby fluid eutectiferous silicon-rich alloy is produced and infiltrated through the interstices between the diamond crystals producing, upon cooling, an adherently bonded integral body.