Alpha alumina-based abrasive grain containing silica and iron oxide
US5611829A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 26, 1996 |
| Grant date | Mar 18, 1997 |
| Priority date | — |
| Expiry date | Jun 26, 2016 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09K3/1436
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.