A CVD diamond layer for use as an insert in an abrasive tool characterized by the following features: (i) the layer contains boron dopant atoms in a concentration of at least 0.05 atomic percent; (ii) an average tensile rupture strength of at least 600 MPa with the nucleation phase in tension, and at least 300 MPa with the growth face in tension, both such tensile rupture strengths being measured by a three point bend test on a sample 18 mm long, 2 mm wide and a thickness of 1.4 mm or smaller.

In a diamond bit having mud channels formed in the face thereof, a single row of diamonds is arranged along each mud channel. The diamonds are positioned so that the scraping edge of each diamond is between two perpendicularly arranged planes of the diamond and so that one of these planes lies in the wall of the mud channel.

A drilling section for diamond drills consisting of a drill bit and a reamer wherein the direction of the drill hole is controlled by the provision of cylindrical surfaces behind the cutting portion of the bit and the reamer, such cylindrical surfaces having a diameter which is slightly less than that of the cutting portion and the reamer. The outer surfaces of the drill assembly including the cutting portion of the bit and the core bar may be provided with spiral grooves to assist the circulati...

A method of determining whether a diamond is the same as or different to a known diamond characterized by the steps of producing one or more records of internal defects of the diamond using X-ray topography and comparing the record or records so produced with a similar record or records produced from the known diamond.

A process for growing by chemical vapor deposition a heteroepitaxial single crystal diamond is disclosed. The process provides a substrate which enables the growth of single crystal diamond which is vapor coated on an iridium film. An intermediate process for producing a composite composition with diamond nuclei is also described. Further described are composite compositions of metal oxide, iridium and single crystal diamond films or diamond nuclei. Single crystal diamond is useful in a variety ...

A diamond saw for cutting hard materials, in which a steel plate is fixed with a sintered body consisting of diamond abrasive granules and a bonding metal powder, characterized in that a plurality of grooves having openings are provided at the edges of both the front and back side faces of said sintered body.

A diamond bit, the diamonds in the sidewall thereof being set in a blunt position in a direction radial to the central axis of the bit as well as in a cutting position in a direction tangential to a helical line passing through the cutting tip of the diamond and having a central axis coinciding with the central axis of the bit.

A diamond tool includes a tubular shank which has a cylindrical end portion, and a friction ring carrying a diamond having a cylindrical recess which freely receives said cylindrical end portion of the shank for rotation of the ring on the shank to turn the diamond from time-to-time, and there are radial openings in the shank containing balls which are pressed by a screw pressed pointed rod in the shank into snug but yieldable frictional contact with the wall of said recess to hold the ring in a...

The synthesis of diamonds from salts of iron, manganese, calcium and magnesium is disclosed. Specifically, such synthesis, in a closed system, has involved carbonate and oxylate salts of the indicated metals. The reaction occurs at temperatures between 550.degree. and 1600.degree. C., higher temperatures requiring higher reaction pressures; specifically, the production of synthetic diamonds from ferrous carbonate is disclosed. The ferrous carbonate was packed into a platinum capsule which was se...

A diamond paste to be used for treating surfaces of workpieces comprising diamond powder in a mechanical mixture with surface-active and lubricating (cooling) components. The components of the paste are used in the following quantities (in % by weight): diamond powder filler: 30-2 green silicon carbide: up to 38 aerosil: up to 5 surface-active substance stearine: 20-5 low-molecular weight heat-resistant synthetic rubber: 20-40 lubricating cooling substance castor oil: 15-5 vaseline: 15-5