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:
Dec. 07, 1993
Filed:
May. 13, 1991
Kunio Komaki, Tokyo, JP;
Takashi Fujimaki, Tokyo, JP;
Masaaki Yanagisawa, Tokyo, JP;
Yoichi Hirose, Saitama 344-01, JP;
Showa Denko Kabushiki Kaisha, Tokyo, JP;
Other;
Abstract
A composite diamond grain which comprises a heat-resistant grain as a nucleus and discrete diamond crystal particles distributed on the surface of the grain or diamond crystal films formed to cover the entire surface of the grain and a method for producing the composite diamond grain by the vapor-phase process are disclosed. For the filament method which is one form of the vapor-phase method, tantalum is useful as the material for the filament. Since tantalum is susceptible of embrittlement by hydrogen, a treatment to be performed on tantalum for the elimination of this drawback is also disclosed.