5286results about "Grinding devices" patented technology

Precursor alpha alumina abrasive particles in a mold are subjected to a drying process that cracks or fractures at least a majority of the precursor abrasive particles into at least two pieces thereby producing abrasive shards having a smaller size than the mold cavity from which they were made. The smaller abrasive shards, once formed, could be reassembled like jigsaw puzzle pieces to reproduce the original cavity shape of the mold from which they were made. The cracking or fracturing of the precursor abrasive particles is believed to occur by ensuring that the surface tension of the abrasive dispersion to the walls of the mold is greater than the internal attractive forces of the abrasive dispersion as the abrasive dispersion is dried within the mold cavity.

Flexible abrasive sheet articles having precision thickness flat-topped raised island structures that are coated with a monolayer of equal sized abrasive agglomerate are described. Methods of producing high quality equal-sized spherical shaped composite abrasive agglomerate beads containing small diamond abrasive particles are described. Beads are produced by level-filling fine mesh screens or perforated sheets with a water based metal oxide slurry containing abrasive particles and then using a fluid jet to eject the abrasive slurry lumps from the individual screen cells into a dehydrating environment. Surface tension forces form the ejected liquid lumps into spheres that are solidified and then heated in a furnace to form ceramic beads. These porous ceramic abrasive beads can be bonded directly onto the flat planar surface of a flexible backing material or they can be bonded onto raised island surfaces to form rectangular or disk abrasive sheet articles. Abrasive articles having equal sized abrasive beads are particularly suited for lapping and raised island articles are suited for high speed lapping. Non-abrasive equal-sized beads can also be formed using this simple bead manufacturing process, which requires only a very low capital investment.

Polymer-based pads useful for polishing objects, particularly integrated circuits, having interconnected porosity which is uniform in all directions, and where the solid portion of said pad consists of a uniform continuously interconnected polymer material of greater than 50% of the gross volume of the article, are produced directly to final shape and dimension by pressure sintering powder compacts of thermoplastic polymer at a temperature above the glass transition temperature but not exceeding the melting point of the polymer and at a pressure in excess of 100 psi in a mold having the desired final pad dimensions. In a preferred version, a mixture of two polymer powders is used, where one polymer has a lower melting point than the other. When pressure sintered at a temperature not to exceed the melting point of the lower melting powder, the increased stiffness afforded by incorporation of the higher melting polymer component gives improved mechanical strength to the sintered product. Conditions for producing the pads of this invention are such that the polymer powder particles from which the pads are produced essentially retain their original shape and are point bonded to form the pad.

A doubled-sided PCD or PCBN compact as well as a new multi-layered PCD and PCBN can be produced using high pressure high temperature processes allowing for increased effective thickness of abrasive tools. A polycrystalline compact can include a substrate having a first surface and a second surface which are non-contiguous. Additionally, a first polycrystalline layer can be attached to the first surface of the substrate and a second polycrystalline layer attached to the second surface of the substrate. The first and second polycrystalline layers can include superabrasive particles bonded together by sintering or chemical bonding with an additional metal. Such double-sided PCD and PCBN compacts as well as a new multiple layered PCD and PCBN allow for increased effective thickness of a tool without suffering from non-homogenous results typical of standard PCD and PCBN compacts, regardless of superabrasive particle size. Each polycrystalline layer can include superabrasive particles of varying particle sizes such that the final tool is tailored for specific abrading characteristics. Such doubled-sided and / or multiple layered PCD and PCBN compacts can be incorporated into a wide variety of abrasive tools for use in cutting, milling, grinding, polishing, drilling and other similar abrasive applications.

PCD materials comprise a diamond body having bonded diamond crystals and interstitial regions disposed among the crystals. The diamond body is formed from diamond grains and a catalyst material at high pressure / high temperature conditions. The diamond grains have an average particle size of about 0.03 mm or greater. At least a portion of the diamond body has a high diamond volume content of greater than about 93 percent by volume. The entire diamond body can comprise high volume content diamond or a region of the diamond body can comprise the high volume content diamond. The diamond body includes a working surface, a first region substantially free of the catalyst material, and a second region that includes the catalyst material. At least a portion of the first region extends from the working surface to depth of from about 0.01 to about 0.1 mm.

A polycrystalline diamond abrasive element, particularly a cutting element, comprises a table of polycrystalline diamond bonded to a substrate, particularly a cemented carbide substrate, along a non-planar interface. The non-planar interface typically has a cruciform configuration. The polycrystalline diamond has a high wear-resistance, and has a region adjacent the working surface lean in catalysing material and a region rich in catalysing material. The region lean in catalysing material extends to a depth of 40 to 90 microns, which is much shallower than in the prior art. Notwithstanding the shallow region lean in catalysing material, the polycrystalline diamond cutters have a wear resistance, impact strength and cutter life comparable to that of prior art cutter, but requiring only 20% of the treatment times of the prior art cutters.

A method of forming a thermally stable cutting element that includes disposing at least a portion of a polycrystalline abrasive body containing a catalyzing material to be leached into a leaching agent; and subjecting the polycrystalline abrasive object to an elevated temperature and pressure is disclosed. Thermally stable cutting elements and systems and other methods for forming thermally stable cutting elements are also disclosed.

A doubled-sided PCBN and / or PCD compact can be produced using high pressure high temperature processes allowing for increased effective thickness of abrasive tools, decreased delamination, and increased useful service life. A polycrystalline compact can include a substrate having a first surface and a second surface which are non-contiguous. Additionally, a first polycrystalline layer can be attached to the first surface of the substrate and a second polycrystalline layer attached to the second surface of the substrate. The first and second polycrystalline layers can be attached to the substrate via an intermediate layer containing superabrasive particles. Such double-sided PCBN and PCD compacts allow for increased effective thickness of a tool without suffering from non-homogenous results typical of standard PCD and PCBN compacts, regardless of superabrasive particle size. Each polycrystalline layer can include superabrasive particles of varying particle sizes such that the final tool is tailored for specific abrading characteristics. Such doubled-sided PCBN and PCD compacts can be incorporated into a wide variety of abrasive tools for use in cutting, milling, grinding, polishing, drilling and other similar abrasive applications.

Method for making alpha alumina-based abrasive grain, wherein during an impregnation step of the method, alpha alumina-based ceramic precursor particles conchoidally fracture. The abrasive grain can be incorporated into abrasive products such as coated abrasives, bonded abrasives, and non-woven abrasives.

A method for accelerated leaching of binder-catalyst material from the polycrystalline diamond structure of a PDC is disclosed. The PDC is sonochemically leached. Also disclosed are fixture, equipment and a system for sonochemically leaching the polycrystalline diamond structure of a PDC.

Thermally-stable polycrystalline diamond materials of this invention comprise a first phase including a plurality of bonded together diamond crystals, and a second phase including a reaction product formed between a binder / catalyst material and a material reactive with the binder / catalyst material. The reaction product is disposed within interstitial regions of the polycrystalline diamond material that exists between the bonded diamond crystals. The first and second phases are formed during a single high pressure / high temperature process condition. The reaction product has a coefficient of thermal expansion that is relatively closer to that of the bonded together diamond crystals than that of the binder / catalyst material, thereby providing an improved degree of thermal stability to the polycrystalline diamond material.

A method of producing equal-sized spherical shaped beads of a wide range of materials is described. These beads are produced by forming the parent bead material into a liquid solution and by filling equal volume cells in a sheet with the liquid solution. The sheet cells establish the volumes of each of the cell mixture volumes which are then ejected from the cells by an impinging fluid. Surface tension forces acting on the ejected equal sized solution entities form them into spherical beads. The ejected beads are then subjected to a solidification environment which solidifies the spherical beads. The beads can be solid or porous or hollow and can also have bead coatings of multiple material layers.

The invention provides a polishing pad by which optical materials such as lenses, reflecting mirrors etc., or materials requiring a high degree of surface planarity, as in the polishing of silicone wafers, glass substrates or aluminum substrates for hard disks, or general metal polishing, can be flattened with stability and high polishing efficiency. The invention also provides a polishing pad for semiconductor wafers, which is superior in planarizing characteristic, is free from scratches and can be produced at low cost. There is provided a polishing pad which is free from dechucking error so that neither damage to wafers nor decrease in operating efficiency occurs. There is provided a polishing pad which is satisfactory in planarity, within wafer uniformity, and polishing rate and produces less change in polishing rate. There is provided a polishing pad which can make planarity improvement and scratch decrease compatible.

A structured abrasive article, methods of making an abrasive article, and methods of using an abrasive article. The abrasive composites forming the abrasive article have a height of at least 500 micrometers, and the abrasive particles in the composites have an average particle size of at least 40 micrometers, in some embodiments, at least about 85 micrometers. The large topography composites, together with the large ceramic abrasive particles, provides an abrasive article that has a more consistent cut, a longer cutting life, and a more consistent surface finish than conventional make / coat abrasive articles with the same size and type of abrasive particles. Additionally, the large topography composites, together with the large ceramic abrasive particles, provide an abrasive article that has a more consistent cut, a longer cutting life, and a more consistent surface finish than structured abrasive articles having a smaller topography, even with the same abrasive particles.

Bonded abrasive tools, e.g., grinding wheels, can be reinforced using, for instance, one or more fibreglass web(s) having a surface of glass per unit of at least 0.2. Alternatively or in addition, the fibreglass web has a thickness of 2 mm or less. The web can be designed to provide improved adhesion between the fibreglass reinforcement and the mixture employed to form the bonded abrasive tool. In some examples, the middle reinforcement at the neutral zone of the wheel can be eliminated or minimized.

A bonded abrasive tool comprises a blend of abrasive grains and a bond component. The blend of abrasive grains comprises a filamentary sol-gel alumina abrasive grain and agglomerated abrasive grain granules. A bonded abrasive tool comprising an agglomerate of filamentary sol-gel alumina abrasive and non-filamentary abrasive grains, and a bond component is also disclosed. The filamentary sol-gel alumina abrasive grain has a length-to-cross-sectional-width aspect ratio of greater than 1.0. The agglomerated abrasive grain granules comprise a plurality of abrasive grains held in a three-dimensional shape by a binding material. A method of making such a bonded abrasive tool as described above is also disclosed.

A cutting element for use in a drill bit for drilling subterranean formations includes a cutting body having a substrate including a rear surface, an upper surface, and a peripheral side surface extending between the rear surface and the upper surface, and a superabrasive layer overlying the upper surface of the substrate. The cutting element further includes a sleeve surrounding the peripheral side surface of the cutting body and comprising a superabrasive layer bonded to an external surface of the sleeve.

Nonwoven abrasive articles, particularly lofty nonwoven abrasive articles, with a textured, non-planar surface and an abrasive coating thereon. The coating may cover the entire surface or only portions of the surface. The textured surface, composed of peaks or high regions and valleys or recessed regions, provides improved cut performance over nonwoven abrasive articles having a generally planar abrading surface.

Coated abrasives comprising shaped structures deposited on a backing can be given increased versatility can be made by a process in which the shaped structure is imposed on a structure deposited in layers on the backing before the shaped structures are formed such that different characteristics are revealed as the structure is eroded during use.

A superabrasive wire saw having a plurality of individual coated superabrasive particles attached to a wire with an organic binder is disclosed and described. The superabrasive particle can be coated with a solidified coating of a molten braze alloy that is chemically bonded to the superabrasive particle. The organic binder can optionally contain filler materials and / or an organometallic coupling agent to improve the retention of coated superabrasive particles. The resulting superabrasive wire saws can be produced having diameters of less than 0.5 mm which significantly reduce kerf loss. Various methods for making and using such a superabrasive wire saw are additionally disclosed and described.

The polishing pad of this invention is a polishing pad effecting stable planarizing processing, at high polishing rate, materials requiring surface flatness at high level, such as a silicon wafer for semiconductor devices, a magnetic disk, an optical lens etc. This invention provides a polishing pad which can be subjected to surface processing to form a sheet or grooves, is excellent in thickness accuracy, attains a high polishing rate, achieves a uniform polishing rate, and also provides a polishing pad which is free of quality variations resulting from an individual variation, easily enables a change the surface patterns, enables fine surface pattern, is compatible with various materials to be polished, is free of burrs upon forming the pattern. This invention provides a polishing pad which can have abrasive grains mixed at very high density without using slurry, and generates few scratches by preventing aggregation of abrasive grains dispersed therein. The polishing pad of this invention has a polishing layer formed from a curing composition to be cured with energy rays, the polishing layer being formed surface pattern thereon by photolithography. The polishing pad of this invention comprises a polishing layer resin having abrasive grains dispersed therein, the resin containing ionic groups in the range of 20 to 1500 eq / ton.

A single-use grinding tool includes a wheel portion having a profiled recess (e.g., such as a U, V, or bowl shape) extending circumferentially along the wheel portion's periphery. A multi-layered bonded abrasive (e.g., 3-dimensional matrix of abrasive grains and bond material, or multiple layers of abrasive tape) is conformably coated or otherwise applied in a uniform thickness along the profiled recess. The bonded abrasive in one particular case includes a metal bond with diamonds. However, organic, resinous, vitrified, and hybrid bonds, as well as other abrasive grit types, can be used. The wheel portion is supported by an arbor portion which may be removably coupled to the wheel portion, or formed integrally with the wheel portion. The tool is useful, for example, in edge grinding a workpiece, such as sheet glass. Methods of tool use and tool manufacture are disclosed as well.

A polycrystalline diamond compact cutter that includes a thermally stable polycrystalline diamond layer, a carbide substrate, and a polycrystalline cubic boron nitride layer interposed between the thermally stable polycrystalline diamond layer and the carbide substrate is disclosed. A method of forming a polycrystalline diamond compact cutter that includes the steps of providing a carbide substrate, disposing a polycrystalline cubic boron nitride layer on the carbide substrate, disposing a polycrystalline diamond layer on the polycrystalline cubic boron nitride layer, and treating at least a portion of the polycrystalline diamond layer to form a thermally stable polycrystalline diamond layer is also disclosed.

Superabrasive tools and methods for the making thereof are disclosed and described. In one aspect, superabrasive particles are chemically bonded to a matrix support material according to a predetermined pattern by a braze alloy. The brazing alloy may be provided as a powder, thin sheet, or sheet of amorphous alloy. A template having a plurality of apertures arranged in a predetermined pattern may be used to place the superabrasive particles on a given substrate or matrix support material.