A grinding wheel includes a disc-like member and a grinding layer disposed on an outer peripheral surface of the disc-like member. The grinding layer includes a plurality of circumferentially-divided grinding chips which are divided in a circumferential direction. Each of the circumferentially-divided grinding chips is formed by arranging a first grinding chip and a second grinding chip in the axis direction, the first grinding chip and the second grinding chip having different properties. A boundary portion between the first grinding chip and the second grinding chip of at least three circumferentially-divided grinding chips continuously arranged in the circumferential direction are arranged toward a predetermined direction in the axis direction in the order in which the circumferentially-divided grinding chips are arranged.

A superabrasive element includes a substrate and a superabrasive table bonded to the substrate, the superabrasive table including a polished surface having a polished finish, the polished surface extending over at least a central, apical region of the superabrasive table, and an unpolished surface including an unpolished finish, the unpolished surface surrounding a majority of the polished surface. A method of manufacturing a superabrasive element includes providing a superabrasive element having a substrate and a superabrasive table bonded to the substrate and polishing at least a central, apical region of the superabrasive table to form a polished surface, without polishing an unpolished surface of the superabrasive table, the unpolished surface surrounding a majority of the polished surface.

A method of manufacturing an abrasive member, in particular having the general shape of a disc such as a cutting or grinding disc, comprises arranging a reinforcing insert or reinforcing member into a mold between a layer of curable abrasive resin compound, in particular a layer of curable abrasive granulate, a backing member such that at least a section of the reinforcing insert or reinforcing member is in direct physical contact with the curable abrasive resin compound, the reinforcing insert or reinforcing member is at least partially covered by the backing member and at least a section of the backing member is in direct physical contact with the curable abrasive resin compound; bonding the reinforcing insert or reinforcing member and the backing member by curing the curable abrasive resin compound, wherein the cured abrasive resin compound forms an abrasive layer of the abrasive member.

Methods for manufacturing bonded abrasive articles, for example vitrified bonded grinding wheels. A bondable abrasive composition is prepared including abrasive particles, a binder medium and a gamma-pyrone pore inducing material, such as ethyl maltol. A precursor abrasive structure is formed from the composition. The gamma-pyrone pore inducing material is removed from the precursor abrasive structure to provide a porous precursor abrasive structure that is further processed to provide a bonded abrasive article. In some embodiments, the binder medium includes a vitreous bonding material, and the bonded abrasive article is a porous vitrified bonded grinding wheel.

A composite polycrystal contains polycrystalline diamond formed of diamond grains that are directly bonded mutually, and non-diamond carbon dispersed in the polycrystalline diamond, and has a concentration of contained hydrogen of greater than 1000 ppm and less than or equal to 20000 ppm.

A super hard polycrystalline construction comprises a body of polycrystalline super hard material, said body having an exposed working surface, a substrate attached to the body of polycrystalline super hard material along an interface and a plurality of apertures or channels. One or more of said apertures or channels extend(s) from the exposed working surface of the body into the substrate.

A machining segment for a machining tool which is rotatable in a direction of rotation about an axis of rotation includes an underside where the machining segment is connectable to a basic body of the machining tool by the underside. A machining zone has a matrix material and a plurality of first hard material particles where the plurality of first hard material particles are disposed in the matrix material in accordance with a defined particle pattern. Each of the plurality of first hard material particles has a respective projection in relation to the matrix material on an upper side of the machining segment. The projection of at least one of the plurality of first hard material particles is greater than 400 μm.

The present disclosure provides improved rail grinding tools. Precision-shaped grains (PSGs), such as PSGs manufactured by 3M® company, provide significant performance improvement in resin-bond and vitrified bond grinding wheels. The use of PSG improves the performance of portable bonded wheels and precision grinding wheels, such as resin bond roll grinding wheels, flute grinding wheels, vitrified gear grinding wheels, cylindrical grinding wheels, and surface grinding wheels. The formation and composition of (e.g., monolithic) and multiple-layer PSG grinding tools described herein provides improved performance of rail grinding tools.

Various embodiments disclosed relate to a partially shaped abrasive particle. The partially shaped abrasive particle includes a shaped portion, engineered to have a polygonal shape, and an irregular portion. The irregular portion is coupled to a base of the shaped portion, forming a single partially shaped abrasive particle.

The present invention provides methods for making a pre-conditioned chemical mechanical (CMP) polishing pad having a pad surface microtexture effective for polishing comprising grinding the surface of the CMP polishing pad having a radius with a rotary grinder while it is held in place on a flat bed platen surface, the rotary grinder having a grinding surface disposed parallel to or substantially parallel to the surface of the flat bed platen and made of a porous abrasive material, wherein the resulting CMP polishing pad has a surface roughness of from 0.01 μm to 25 μm, Sq. The present invention also provides a CMP polishing pad having a series of visibly intersecting arcs on the polishing layer surface, the intersecting arcs having a radius of curvature equal to or greater than half of the radius of curvature of the pad and extending all the way around the surface of the pad in radial symmetry around the center point of the pad.