Method for producing .alpha.-form silicon nitride fine powders
US4590053A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 24, 1985 |
| Grant date | May 20, 1986 |
| Priority date | — |
| Expiry date | Jun 24, 2005 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01P2006/12
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A method for producing a high-grade fine powder of .alpha.-form silicon nitride (.alpha.-Si.sub.3 N.sub.4) for use as sintered bodies excellent in heat-stability and mechanical strength which comprises heat-treating, in an atmosphere containing nitrogen, a mixture prepared by adding additive: PA0 a mixture of at least one of Mg, Ca, and compounds thereof with 0.01-1 part by weight of silicon nitride powder, in a total amount of 0.001-0.1 part by weight calculated in terms of elemental weight(s) of Mg or/and Ca, and 1 part or less by weight of silicon nitride powder, to 1 part by weight of silicon oxide powder and 0.4-4 parts by weight of carbon powder.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.