Process for preparing cubic boron nitride
US4409193A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 3, 1982 |
| Grant date | Oct 11, 1983 |
| Priority date | — |
| Expiry date | Mar 3, 2002 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC04B35/5831
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A process for preparing cubic boron nitride comprises heating hexagonal boron nitride and magnesium boron nitride at a temperature of at least 1350.degree. C. under a pressure at which the cubic boron nitride is thermodynamically stable, whereby the cubic boron having high strength and high purity can readily be obtainable. Also disclosed is a process for the preparation of magnesium boron useful as a starting material for the above process. This process comprises mixing hexagonal boron nitride and magnesium nitride or metal magnesium in a molar ratio of hexagonal boron nitride/magnesium being at least 0.6, and heating the mixture thus obtained, at a temperature of from 950.degree. to 1250.degree. C. under atmospheric pressure in a non-oxidizing atmosphere, e.g. a nitrogen atmosphere.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.