A method of making a bonded, coherent material comprising a mass of diamond crystals in a matrix, which optionally contains another phase. The method includes the steps of providing a source of diamond crystals, providing a plurality of diamond centers defined by diamond crystals, producing a reaction mass by bringing the source and growth centers into contact with a solvent/catalyst, subjecting the reaction mass to conditions of elevated temperature and pressure suitable for crystal growth in t...

A diamond cutter consisting of a polycrystalline diamond layer sintered to a cylindrically shaped tungsten carbide substrate is brazed to a cylindrically shaped mounting surface formed at a cutting end of a tungsten carbide insert body. The cylindrically shaped mounting surface of the insert body is the same diameter as the tungsten carbide substrate hence no fillet of braze material can form adjacent the juncture between the substrate and the insert body at the cutting end of the insert thereby...

Diamond compact composed of 60-95 volume % diamond crystals plastically deformed into a closely packed, rigid structure with contacts between the diamond crystals over extended mating surfaces arising from the plastic deformation. The diamond crystals are bonded together by an interstitial bonding material composed of a refractory carbide, such as silicon carbide, or a bonding material composed of a metal such as rhenium and a refractory carbide formed by reaction of a metallic bonding agent, su...

A diamond film is grown on a substrate by providing a non-diamond substrate which has a face-centered cubic (fcc) crystal structure and small crystal lattice mismatch with the lattice of diamond, implanting carbon atoms into the crystal lattice of the substrate and causing the implanted carbon atoms to diffuse out of the substrate and grow epitaxially on the surface of the substrate. The preferred substrate is an fcc metal such as copper, nickel, fcc iron, fcc cobalt or fcc chromium.

An improved roller for supporting an overhead sliding door to a track, the roller comprising a diamond configurated roller element movable along a transversely configurated diamond track, the roller being mounted on a roller bearing at one end of a shaft fitted into a bracket plate and urged into longitudinal or axial adjustment by means of a back up compression spring.

An information mark invisible to the naked eye is applied to the polished facet of a diamond gemstone by coating the diamond gemstone surface with an electrically conductive layer so as to prevent the diamond becoming charged, forming the mark with a focused ion beam, and cleaning the diamond surface with a powerful oxidizing agent to reveal a mark having an appropriate depth, which does not detrimentally affect the clarity or color grade of the diamond.

An invisible information mark is provided on a facet of a diamond gemstone by applying a plasma resist to the exposed surface of the gemstone, applying an electrically conducting layer of metal to the region where the information mark is to be formed, ablating a selected zone of the metal and resist layers by ultraviolet laser thus forming a mask on the surface of the facet, electrically connecting the metal layer and plasma etching the facet through the mask, thus forming a mark of appropriate ...

In order to test whether a diamond has had a layer a synthetic diamond deposited thereon, the diamond is radiated with ultraviolet radiation so as to form a pattern of beams of refracted and reflected radiation, the pattern of refracted and reflected radiation being observed on a screen behind the diamond.

A method for mapping the crystal structure of a diamond comprises placing the diamond in a beam of monochromatic laser radiation, filtering the resultant scattered Raman radiation, and measuring the intensity of the filtered radiation at one or more different orientations of the diamond which may be compared with records of known diamonds to identify the diamond.

The invention provides elongate synthetic RD diamond particles, each particle having a long axis and a short transverse axis, the ratio of the long axis to the short axis being at least 3 to 1. Each particle generally has a rib bed structure down its long axis, the ribs of the structure being traces of {111} crystallographic planes and the long axis providing a backbone for the structure and being in the direction <100> crystallographic direction. The invention further provides a resin bon...