Process for making silicon nitride cutting tool material
US6066582A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 14, 1999 |
| Grant date | May 23, 2000 |
| Priority date | — |
| Expiry date | Jan 14, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T407/27
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
The ceramic cutting tool material according to the present invention comprises a beta silicon nitride matrix with total amount of 0.5-10 weight %, preferably 0.5-6 weight %, of an intergranular phase and 0.05-3 weight % of at least one secondary crystalline phase of a transition metal carbide, nitride, carbonitride and/or silicide present as spherical particles with a size of 0.1-2 .mu.m, preferably submicron (0.01-1 .mu.m). The transition metal is preferably niobium and/or tantalum. The material has less than 1 volume %, preferably less than 0.3 volume %, porosity. The beta silicon nitride grains are to at least 10%, preferably more than 20%, elongated with an aspect ratio greater than 3, preferably greater than 5. The grain diameter of the beta silicon nitride grains is in the range of 0.2-10 .mu.m, preferably 0.2-5 .mu.m, and most preferably 0.2-3 .mu.m.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.