Abrasive grain with metal oxide coating, method of making same and abrasive products
AssigneeMinnesota Mining and Manufacturing Company
InventorAhmet Celikkaya
Life of this patent
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Abstract
A method of preparing preferred abrasive grain material is provided. The method involves steps of coating a non-sintered aluminum base particles with a metal alkoxide containing coating; heating to convert the coating to a metal oxide coating; and then sinter the base particles to provide sintered particles having an alpha-alumina-based core with an autogenously bonded metal oxide coating. The invention also concerns improved abrasive grain materials and abrasive products including the improved abrasive grain materials therein.
Claims18
A method of making ceramic abrasive grain, said method comprising the steps of:
- (a) providing a mass of particles comprising alpha-alumina precursor material each particle of which is sinterable to an alpha-alumina-based abrasive particle of said abrasive grain;
- (b) coating said particles with a coating composition comprising metal alkoxide to provide coated particles, said coating being capable of converting to a metal oxide coating which is autogenously bonded to the surface of each of said particles upon heating;
- and
- (c) heating said coated particles under conditions which convert said coating to a metal oxide coating and sinter said particles to provide alpha alumina-based particles.
A method according to claim wherein step (c) includes:
- (i) hydrolyzing said metal alkoxide coating to a coating of metal hydroxide;
- and
- (ii) heating said coating of metal hydroxide to a temperature of at least 400.degree. C.
Ceramic abrasive grain comprising
- a plurality of sintered particles, each particle comprising:
- (i) an alpha-alumina-based core;
- and,
- (ii) a metal oxide coating autogenously bonded to said alpha-alumina-based core;
- said metal oxide coating comprising randomly shaped metal oxide islands each island of which being at least about 10 micrometers in length and less than about 5 micrometers in thickness.
Dependencies are inferred from the claim text.