Submicron alpha alumina high temperature bonded abrasives

摘要

A high temperature bonded abrasive includes alumina abrasive grits, and a vitreous bond matrix in which the alumina abrasive grits are distributed, the vitreous bond matrix having a cure temperature not less than 1000° C. The alumina abrasive grits include polycrystalline alpha alumina having a fine crystalline microstructure characterized by an alpha alumina average domain size not greater than 500 nm, and the alumina abrasive grits further include a pinning agent that is a dispersed phase in the polycrystalline alpha alumina.

主权项

1. A method of forming a high temperature bonded abrasive component, comprising:
combining an alpha alumina seed material, an alpha alumina precursor and a pinning agent in form of a gelled aqueous slurry, wherein the pinning agent comprises an oxide of boron, titanium, zirconium, a rare earth element, or a combination thereof and has an average particulate size not greater than 5 microns; forming fine crystalline microstructure alpha alumina abrasive grits, by heat treating the combined alpha-alumina precursor, the alpha alumina seed material, and the pinning agent at a temperature not less than 1350° C. wherein the alumina abrasive grits have an average crystalline domain size not greater than 300 nm after heat treating and the pinning agent forms a dispersed phase in the alpha alumina abrasive grits; forming a shaped body containing the alpha alumina grits with a vitreous bond matrix material; and heat treating the shaped body at a cure temperature, not less than 1000° C. and above a melting point of the vitreous bond matrix material, the vitreous bond matrix material bonding individual alumina abrasive grits to each other.