Silicon nitride sintered body and method for producing same
US5114888A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 15, 1990 |
| Grant date | May 19, 1992 |
| Priority date | — |
| Expiry date | Nov 15, 2010 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC04B35/5935
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Silicon nitride base sintered body consists of: 1 to 20 wt % (as oxides) of at least one of rare earth elements; 0.5 to 8 wt % of V (as V.sub.2 O.sub.5); 0.5 to 8 wt % (as oxides) of at least one of Nb, Ta, Cr, Mo and W; sum of the Va and VIa group elements according to the Periodic Table of the International Version (as oxides) being 1 to 10 wt %; and balance silicon nitride. It has high strength of 690-880 MPa (70-90 kgf/mm.sup.2) and high oxidation resistance both at 1350.degree. C. It is produced by 2 stage gas-pressure sintering in pressurized N.sub.2 atmosphere, primarily at 1700.degree.-1900.degree. C. at 1 MPa (10 atm) or less and secondarily at 1600.degree.-1900 C. at 10 MPa (100 atm) or above.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.