The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 11, 1983
Filed:
Mar. 03, 1982
Tadao Sato, Sakura, JP;
Tadashi Endo, Sakura, JP;
Osamu Fukunaga, Sakura, JP;
Minoru Iwata, Matsudo, JP;
National Institute for Researches in Inorganic Materials, Ibaraki, JP;
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.