Abstract: A composite abrasive product comprises a refractory carbide support and a ring-shaped compact having a rotational symmetry about an axis of the support. The compact has an axial thickness which is small as compared with the axial thickness of the support and a substantially triangular axial cross-section, said compact having a face metallurgically bonded to a chamfered circumferential part of the support and the two remaining faces joining at a cutting edge. A method for manufacturing such a product is also disclosed.

Abstract: An abrasive is provided having an active phase comprising a sintered product comprising diamond grains, each grain being linked directly to its neighbors by bridging to exhibit a polycrystalline structure, and a support consisting essentially of tungsten carbide. The tungsten carbide support comprises a chromium binder phase including 6 to 15% of carbide. The relative proportions by weight of nickel and chromium of the binder phase vary from 60 to 90% to 40 to 100%, respectively. The abrasive is made by placing a layer of diamond grains into a cupel, covering this layer with a tungsten carbide layer including a nickel-chromium mixture to provide the support, subjecting the stack thus produced to a temperature and a pressure sufficient to cause sintering in the plastic phase of the diamond grains and to assure the binding of the compact thus obtained on the support. Drilling and machine tools can be equipped with the abrasive product of the invention.

Abstract: For preparing a composite abrasive product having an active part, formed by a compact containing grains of ultra-hard product representing more than 80% per volume of the compact, each grain being bonded directly to its neighbors so that the compact has a polycrystalline structure, and by a hard and refractory support bonded to the compact, formed essentially of a refractory carbide such tungsten carbide, characterized in that: a layer of ultra-hard product grains (PCD or CBN) is placed in contact with components generating an ultra-hard ceramic binder phase in the cell. The powder layer is covered with a thin layer of tungsten coated with a carbide supplying material and, finally, with a tungsten carbide support. The cell containing the stack thus formed is brought to a temperature and a pressure sufficient to cause plastic phase sintering of the ultra-hard product grains with each other and bonding of the compact to the support.

Abstract: A thermostable abrasive diamond product includes a compact formed of diamond grains representing more than 80% by volume of the compact, each grain being bonded directly to its neighbors so as to form a polycrystalline structure. The empty spaces between diamond grains are occupied by a binder face containing silicon and/or titanium and nickel silicon (or titanium) and nickel being alloyed. The compact may be bonded by a metallurgical interface to a substrate of a refractory metal such as tungsten.

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.