The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 08, 1997
Filed:
Jun. 26, 1996
Dwight D Erickson, Oakdale, MN (US);
Larry D Monroe, Eagan, MN (US);
Thomas E Wood, Stillwater, MN (US);
David M Wilson, Bloomington, MN (US);
Minnesota Mining and Manufacturing Company, St. Paul, MN (US);
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.