Abstract: Broadly, the present invention comprises substantially spherical glass globules encapsulating an abrasive particle. The globules are suitable for incorporating into a vitreous bonded grinding wheel and can be made by the steps comprising forming a mixture of glass powder, abrasive particles, and a fluent binder. The binder is fused to form a solid mass containing said glass powder and abrasive particles. The solid mass then is attrited into discrete particles. A desired size fraction of particles of the attrited mass then is separated from any undersize and oversize particle fractions. Finally, the desired size fraction is heated to fuse the glass particles into substantially spherical globules which encapsulate one or more of said abrasive particles. The globules are suitable, then, for incorporation into vitreous bonded grinding wheels.

Abstract: There are provided abrasive particles having a refractory metal oxide coating, a non-metallic precursor to a refractory metal oxide coating, or an elemental metal coating of at least about 20 weight percent of the abrasive particles. In addition abrasive tools such as grinding wheels, especially vitreous bonded grinding wheels, utilizing the coated abrasive particles are provided.

Abstract: There are provided abrasive particles having a refractory metal oxide coating, a non-metallic precursor to a refractory metal oxide coating, or an elemental metal coating of at least about 20 weight percent of the abrasive particles. In addition abrasive tools such as grinding wheels, especially vitreous bonded grinding wheels, utilizing the coated abrasive particles are provided.

Abstract: Disclosed is an apparatus for monitoring the temperature of an implement being brazed to a workpiece. The preferred implement is a polycrystalline diamond composite compact which is brazed to a drill bit or other workpieces. The apparatus comprises an insulated a temperature probe comprising a stiff support rod of predetermined length with a first passageway therethrough. An insulating handle is connected in supporting relationship with the rod and has a second passageway therethrough which communicates with the first passageway. A heat shield is disposed about the handle in the vicinity of its connection with the base portion of the rod. A thermocouple means for generating signals correlative with temperature is disposed at the rod tip and energized from leads extending to an alarm unit.

Abstract: Disclosed is an improvement in method for both dry grinding and wet grinding a workpiece selected from cemented tungsten carbide and combinations of cemented tungsten carbide and steel with a single resin bonded grinding element having metal-coated diamond particles embedded in the grinding surface thereof. Such improved method comprises providing coated diamond particles useful for both dry grinding and wet grinding operations which comprises diamond coated particles coated with two layers of metal, the inner layer consisting of between about 40% and 130% by weight of said diamond particle of nickel and the outer layer consisting of between about 20% and 70% by weight of said diamond particle of silver, wherein the total weight of both said silver and nickel coatings does not exceed above about 200% by weight of the uncoated diamond particle.

Abstract: A shaped confined mass of diamond and/or cubic boron nitride crystals coated with elemental non-diamond carbon, under a partial vacuum, is infiltrated by fluid silicon producing a like-shaped product wherein the crystals are bonded together by a medium comprised of silicon carbide and elemental silicon.