A sol-gel process of producing durable alpha alumina-based ceramic particularly useful as abrasive grain from alpha alumina monohydrate is improved by the addition of a nucleating agent. Improved abrasive products containing the durable ceramic abrasive grains are also provided.

Process for durable sol-gel produced alumina-based ceramic abrasive grain and abrasive products

A method of modifying an exposed surface of a semiconductor wafer that includes the steps of: (a) contacting the surface with a fixed abrasive article having a three-dimensional textured abrasive surface that includes a plurality of abrasive particles and a binder in the form of a pre-determined pattern; and (b) relatively moving the wafer and the fixed abrasive article to modify said surface of the wafer.

Method of modifying an exposed surface of a semiconductor wafer

A method of making abrasive particles having a specified shape and abrasive articles containing abrasive particles having a specified shape. The method for preparing such an abrasive particle comprises the steps of: (a) providing a dispersion containing particles of a precursor of alpha alumina, preferably particles of alpha alumina monohydrate, in a liquid, which liquid comprises a volatile component; (b) providing a mold having a first surface and a second surface opposed to said first surface, said first surface having an opening to a mold cavity having a specified shape; (c) introducing the dispersion into said mold cavity; (d) removing a sufficient portion of the volatile component of the liquid from the dispersion while the dispersion is in the mold cavity, to form a precursor of an abrasive particle having approximately the same shape as the shape of the recess of the mold cavity; (e) removing the precursor of the abrasive particle from the recess of the mold; (f) calcining the removed precursor of the abrasive particle; and (g) sintering the calcined precursor to form the desired abrasive particle.

Shaped abrasive particles and method of making same

Vitrified bonded abrasive bodies prepared from sol gel sintered aluminous grit particles and a vitreous (glass) bond exhibit improved abrasive performance by treating the surfaces of the grit particles so as to give them silica-enriched surfaces.

Vitrified bonded sol gel sintered aluminous abrasive bodies

An improved abrasive grain comprising the sintered product of a porous non-sintered particle having a coating of inorganic material thereon is provided. A preferred method of making such abrasive grains comprises coating the porous base particles with inorganic particles. The preferred step of coating comprises a step of mixing the base particles with a suspension containing the inorganic particles in a carrier fluid. The porous base particles having the coating of inorganic particles thereon are sintered, to generate the ceramic abrasive grain product. The abrasive grains may be incorporated, to advantage, in a variety of abrasive products including, for example, bonded abrasives, nonwoven abrasive products and coated abrasive products.

Abrasive grain, method of making same and abrasive products

The hardness and microstructure of aluminous abrasives produced from alumina gels are enhanced by introduction of seed material as by wet vibratory milling of the material with alumina media, or by the direct addition of very fine alpha alumina particles in the amount of 1% or less.

Abrasive material and method for preparing the same

A filament shaped sintered alumina based abrasive made up predominantly of fine alpha alumina crystals.

Sintered sol gel alumina abrasive filaments

Abrasive material and method

An alumina based ceramic fiber having submicron sized alpha alumina crystals and a density of at least 95% theoretical is obtained from a sol-gel process.

Alumina sol-gel fiber

A shaped ceramic article consists of a high density poly-crystalline phase of submicron, non-cellular, non-faceted α - Al₂O₃ particles of a hardness of at least 18 GPa Randomly dispersed among the submicron particles may be faceted lath-like coarse crystals of alumina The ceramic articles containing high density polycrystal­line alpha alumina are made by sintering a dried alumina gel which has been conditioned by adding submicron sized α-Al₂O₃ particles to the gel or gel precursor This can be done by milling the sol or diluted gel while employing alumina bodies as the grinding medium in the mill or by adding water milled with alumina bodies

Ronald H. van de Merwe

Papers

Abrasive material and method for preparing the same

Sintered sol gel alumina abrasive filaments

Abrasive material and method

Alumina sol-gel fiber

Ceramic shaped article and methods of making same