Abstract: A method and apparatus for improved attachment of an ultra-hard compact, especially a two-layer disk-type PCD compact, to a tool or support surface with a mechanical connection. In general the ultra-hard compact is provided with a tool-engaging threaded end protruding from the compact. The threaded end may be facilitated by a post fitted into a blind hole in the ultra-hard compact, or may be facilitated by a threaded sleeve permanently attached to the ultra-hard compact. In any case, when the ultra-hard compact is threadably engaged into a tool or support surface, the fastening means is hidden with only the wear resistant materials of the ultra-hard compact exposed.

Abstract: A polycrystalline diamond compact for use in cutting operations that require improved impact strength and non-uniform edge wear. The compact includes a substrate, with multiple, laterally spaced, abrasive diamond particle areas segregated by different particle sizes bonded to the substrate. The polycrystalline diamond areas formed of finer size diamond particles provide higher abrasion resistance wear at a slower rate thus producing a non-linear cutting, edge to the work zone. The areas of different average size diamond particles, in one embodiment, are arranged in concentric rings with each ring of a different particle size. Alternating rings may be formed of uniform size diamond a particles. The areas also may be in the form of spaced grooves inlaid from the end surface of polycrystalline diamond layers. The polycrystalline diamond layer may also have a non-planar end with the discrete areas radially spaced across the layer.

Abstract: A method and apparatus for improved attachment of a PCD compact, especially a two-layer disk-type PCD compact, to a tool or support surface with a mechanical connection. In general the PCD compact is provided with a blind bore in the substrate layer, the bore terminating in the substrate layer and opening onto an outer face of the substrate layer intended to engage or abut the tool or support surface. A mechanical fastener is inserted into the blind bore such that it is secured to the PCD compact to form an integral unit with a tool-engaging end of the fastener protruding from the compact. In a preferred form the mechanical fastener is a metal post having at least one, and alternately both, ends threaded for threaded engagement to both the blind bore (which would have its own threads) and suitable threaded openings on the tool.

Abstract: An improved process for providing a bond between carbon substrates using particles of a thermally stable solid is described. In particular, a laminate of a porous carbon substrate and a relatively non-porous carbon substrate using finely divided particles of a thermally stable solid which are in contact with and between both substrates is heated in the presence of a carbonizable gas, such as methane, in a chamber such that the gas contacts the carbon substrates and the particles so that a mutual coating of pyrolytic carbon is deposited on the exposed surfaces of all components and bonds them together. More than two carbon substrates can be bonded using the particles as interlayers between the substrates. The pyrolytic carbon coated composite products are particularly useful as electrodes.

Abstract: An improved method is described for thermally bonding contacting pieces of a thermoplastic material provided in a variable volume confined space surrounded by a combustible gas. The combustible gas is ignited and explosion diffused externally of the pieces of thermoplastic material and thus heats the pieces without damage sufficiently to produce interbonding when the heated pieces are compacted in the confined space. The heated pieces are compacted isostatically or non-isostatically using various apparatus which reduce the volume of the confined space. Preferably a moveable piston is provided in a cylinder to form the confined space for the pieces. The driving means for the piston can be a combustible gas which is ignited or non-combustible gas under pressure or a resilient means or other mechanical means. The products of the method are in the form of a porous mass composed of the interbonded pieces which are undamaged by the explosion.

Abstract: A method for preparing reticulate thermoset resin structures is described. Thermoset or thermosettable resin containing foams, prepared by a method wherein thin membranes dividing contiguous cells in a thin membraned, thick stranded thermoset or thermosettable resin foam with interconnected cells are produced, and are thermally reticulated. The foams are preferably thermally reticulated by providing a combustible gas mixture inside the cells of the foam and then igniting the mixture to destroy the foam membranes. The thermosettable or thermoset reticulate resin structures so produced are particularly useful for preparing carbon structures with the same geometry by heating at elevated temperatures under reducing, inert or vacuum conditions.

Abstract: An improved method is described for thermally bonding contacting pieces of a thermoplastic material provided in a variable volume confined space surrounded by a combustible gas. The combustible gas is ignited and explosion diffused externally of the pieces of thermoplastic material and thus heats the pieces without damage sufficiently to produce interbonding when the heated pieces are compacted in the confined space. The heated pieces are compacted isostatically or non-isostatically using various apparatus which reduce the volume of the confined space. Preferably a moveable piston is provided in a cylinder to form the confined space for the pieces. The driving means for the piston can be a combustible gas which is ignited or non-combustible gas under pressure or a resilient means or other mechanical means. The products of the method are in the form of a porous mass composed of the interbonded pieces which are undamaged by the explosion.