Abstract: By controlling the process parameters and by using a polymeric production tooling having a plurality of mold cavities, different types of shaped abrasive particles selected from the group consisting of abrasive shards, dish-shaped abrasive particles, and shaped abrasive particles with an opening can be produced from the exact same mold. In one embodiment, the mold comprised a plurality of equilateral triangles and fractured precursor abrasive particles, dish-shaped precursor abrasive particles, or precursor shaped abrasive particles with an opening were produced from the same mold.

Abstract: 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.

Abstract: 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.

Abstract: Shaped ceramic articles can be obtained by screen printing the desired shapes from a dispersion of a precursor of the ceramic onto a receiving surface using a transfer assisted technique that applies a differential pressure, at least partially drying the screen printed shapes, and firing them to generate the shaped ceramic articles. Shaped abrasive particles made using lower viscosity sol gels that tended to flow or creep after the screen printing formation were found to have higher grinding performance over screen printed shaped abrasive particles made with higher viscosity sol gels.

Abstract: An abrasive agglomerate includes a plurality of abrasive grains bonded together in a three-dimensional structure by a substantially continuous, non-porous inorganic binder, wherein the abrasive grains have an average size of between about 0.5 microns and about 1500 microns, the inorganic binder is less than about 75 percent, by weight, of the abrasive agglomerate, and the bulk density of the abrasive agglomerate is less than about 90 percent of the bulk density of the abrasive grains.

Abstract: Shaped abrasive particles comprising alpha alumina and having a cross-sectional shape along a longitudinal axis of the shaped abrasive particles, the cross-sectional shape comprising a non-circular cross-sectional plane, and the shaped abrasive particles comprise an Average Roundness Factor of between about 15% to 0%.

Abstract: Abrasive particles comprising dish-shaped abrasive particles each having a sidewall; each of the shaped abrasive particles comprising alpha alumina and having a first face and a second face separated by a thickness, t; and wherein either the first face or the second face is recessed or concave.

Abstract: An abrasive comprising shaped abrasive particles each with an opening. The shaped abrasive particles are formed from alpha alumina and have a first face and a second face separated by a thickness t. The opening in each of the shaped abrasive particles can improve grinding performance by reducing the size of a resulting wear flat, can provide a reservoir for grinding aid, and can improve adhesion to a backing in a coated abrasive article.

Abstract: Abrasive particles comprising shaped abrasive particles each having a sidewall, each of the shaped abrasive particles comprising alpha alumina and having a first face and a second face separated by a sidewall and having a maximum thickness, T; and the shaped abrasive particles further comprising a plurality of grooves on the second face.

Abstract: Abrasive particles comprising shaped abrasive particles each having a sloping sidewall, each of the shaped abrasive particles comprising alpha alumina and having a first face and a second face separated by a thickness, t. The shaped abrasive particles further comprising either: a draft angle ? between the second face and the sloping sidewall, and the draft angle ? is between about 95 degrees to about 130 degrees, or the sloping sidewall having a radius, R, between the first face and the second face and the radius, R, is between about 0.5 to about 2 times the thickness, t.

Abstract: 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.

Abstract: By controlling the process parameters and by using a polymeric production tooling having a plurality of mold cavities, different types of shaped abrasive particles selected from the group consisting of abrasive shards, dish-shaped abrasive particles, and shaped abrasive particles with an opening can be produced from the exact same mold. In one embodiment, the mold comprised a plurality of equilateral triangles and fractured precursor abrasive particles, dish-shaped precursor abrasive particles, or precursor shaped abrasive particles with an opening were produced from the same mold.

Abstract: An abrasive agglomerate includes a plurality of abrasive grains bonded together in a three-dimensional structure by a substantially continuous, non-porous inorganic binder, wherein the abrasive grains have an average size of between about 0.5 microns and about 1500 microns, the inorganic binder is less than about 75 percent, by weight, of the abrasive agglomerate, and the bulk density of the abrasive agglomerate is less than about 90 percent of the bulk density of the abrasive grains.

Abstract: An abrasive agglomerate includes a plurality of abrasive grains bonded together in a three-dimensional structure by a substantially continuous, non-porous inorganic binder, wherein the abrasive grains have an average size of between about 0.5 microns and about 1500 microns, the inorganic binder is less than about 75 percent, by weight, of the abrasive agglomerate, and the bulk density of the abrasive agglomerate is less than about 90 percent of the bulk density of the abrasive grains.

Abstract: Alumina-based abrasive material having at least an internal layer is provided. Preferably, the abrasive material results from co-extrusion of at least two different sols. In some preferred processing, steps to provide multiple internal layers are conducted.

Abstract: Alumina-based abrasive material having at least an internal core structure is provided. Preferably, the abrasive material results from co-extrusion of at least two different sols. In some preferred processing, steps to provide multiple internal core structures are conducted.

Abstract: Alumina-based abrasive material having at least an internal layer is provided. Preferably, the abrasive material results from co-extrusion of at least two different sols. In some preferred processing, steps to provide multiple internal layers are conducted.

Abstract: A method of making an alpha alumina-based ceramic abrasive grain comprising, on a theoretical oxide basis, Al.sub.2 O.sub.3, Fe.sub.2 O.sub.3, and SiO.sub.2. The abrasive grain has a surface roughness height of greater than about 200 nanometers and a density of greater than about 3.50 g/cm.sup.3. Preferably, the alpha alumina-based ceramic abrasive grain has alpha alumina crystallites having an average crystallite size of less than about 0.5 micrometer (more preferably, less than about 0.3 micrometer). The presence of the SiO.sub.2 in combination with Fe.sub.2 O.sub.3 increases the amount of transgranular fracture of the abrasive grain, reduces the alpha alumina crystallite growth during sintering of the abrasive grain, dilates at least one of the unit cell dimensions of the abrasive grain, and generally improves the grinding performance of the abrasive grain.

Abstract: A process for making high porosity boehmite alumina comprising forming an aqueous dispersion of a boehmite alumina which has been obtained by hydrothermally treating an aqueous mixture of a precursor boehmite alumina at a pH of from about 5 to about 9 for a period of time sufficient to convert the greater portion of the precursor boehmite alumina to a colloidal sol, treating the dispersion of the hydrothermally treated alumina to form a viscous gel and subjecting the gel to sufficient shearing force for a sufficient period of time to increase the pore volume by at least 30% and the median pore radius by at least 20%.

Abstract: Alumina-based abrasive grain comprising rare earth oxide and calcium oxide and/or strontium oxide, and a method of making the same. The abrasive grain is useful in abrasive articles, such as coated abrasives, three-dimensional, low density abrasives, and bonded abrasives.