Abstract: High pressure presses for making diamonds and other hard, crystalline materials. The high pressure presses may contain varying numbers of moveable press members: e.g., a tetrahedral press will have four press members while a cubic press will have six press members. The high pressure presses are equipped with at least one hydraulic ram to provide forward and reverse thrusting force. The movable press members are positioned to move along a rectilinear path and converge at a common point. The ram thrusting force is distributed to every press member and the movable press members are guided to move in a simultaneous and synchronous manner by interconnected guide plates and slidable guide rods which comprise a guide system. The guide system allows for the elimination of one or more hydraulic rams such that the total number of hydraulic rams normally connected to each of the moveable press members will be less than the number of press members.

Abstract: A sintered product useful for abrasion- and impact-resistant tools and the like is provided comprising an iron-group metal binder and refractory metal carbide particles, e.g. tungsten carbide, formed in situ during sintering by the exothermic reaction of a carbide-forming refractory metal powder with a carbon source mixed therewith. The sintering is carried out at an elevated temperature and at a pressure at which diamond is stable in the presence of a liquid phase comprised substantially of an iron-group binder metal, refractory metal, and dissolved carbon. The product may optionally contain diamond, up to about 95% in volume, enabling its properties to be tailored for a wide range of applications.

Abstract: A sensor for detecting angular displacement of an object. The sensor comprises a substrate for attachment to the object whose angular displacement is to be sensed and a sensing means attached to the substrate and connectable into an electric circuit. The electric circuit measures the resistance of the sensing means, which changes as a function of the angular displacement. Several embodiments are disclosed, including a conductive elastomer sensor, a conductive ink sensor, a sliding resistor sensor, a force sensitive resistor sensor and a conductive fluid sensor.

Abstract: Scratch-free polished diamond is obtained by rubbing a surface of the diamond to be polished against a smooth complementary diamond surface with sufficient pressure and velocity to heat the surface being polished above the spontaneous thermal degradation temperature of the diamond. Such a method can be used to burnish diamond-on-diamond bearings in as little as ten minutes as compared with up to three weeks by prior polishing techniques. Excessive thermal degradation of the diamond is avoided by cooling the surface being polished, preferably by cooling intermittently. The same techniques are usable for other superhard material such as cubic boron nitride.

Abstract: The invention is a process for preparing a sintered polycrystalline compact of cubic boron nitride (CBN) with substantial intercrystalline bonding, together with the compact produced by the process. A carbon containing material, such as diamond or graphite, is added to a binder material which comprises elemental silicon. The carbon from the carbon containing material reacts with the silicon to form silicon carbide. Having silicon carbide as a constituent of the final product is preferable to having elemental silicon because the silicon carbide does not expand on cooling, and is also harder and more wear resistant than elemental silicon. In this way, the benefits of using elemental silicon in a binder system to enhance intercrystalline bonding of the CBN are realized while avoiding the disadvantages otherwise present. Another advantage is provided in the compact of this invention may be cut into precision shapes with a conventional Electric Discharge Machine (EDM).

Abstract: The invention is a process for preparing a sintered polycrystalline compact of cubic boron nitride, the compact produced by the process, and articles comprising the compact. A mixture is formed of cubic boron nitride grains and from 5 to 20 volume percent of binder material, or sintering aid, consisting essentially of silicon and an aluminum-containing material selected from the group consisting of aluminum, aluminum nitride, aluminum diboride, and mixtures thereof. The mixture is subjected to elevated pressure and temperature conditions sufficient to melt the binder material and at which the boron nitride is thermodynamically stable. The elevated pressure and temperature conditions are maintained for a time sufficient to sinter the compact. The compact is characterized by substantial intergranular CBN-CBN bonding, and has superior wear and impact resistance, thermal conductivity and stability.

Abstract: A high thermal conductivity substrate is formed by making a sintered diamond composite and thereafter modifying the electrical properties of the composite by leaching graphite and other non-diamond materials from the composite and subsequently infusing the leached composite with material having known electrical properties. Alternatively, a diamond composite having high thermal conductivity known electrical properties if prepared and subsequently leached to remove graphite and other materials which interfere with the known electrical properties of the composite material.

Abstract: A high thermal conductivity substrate is formed by making a sintered diamond composite and thereafter modifying the electrical properties of the composite by leaching graphite and other non-diamond materials from the composite and subsequently infusing the leached composite with material having known electrical properties. Alternatively, a diamond composite having high thermal conductivity known electrical properties is prepared and subsequently leached to remove graphite and other materials which interfere with the known electrical properties of the composite material.