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:
Nov. 13, 1990
Filed:
Feb. 14, 1990
Applicant:
Inventors:
Craig A Willkens, Sterling, MA (US);
Stephen D Hartline, Millbury, MA (US);
Normand P Arsenault, Holden, MA (US);
Assignee:
Norton Company, Worcester, MA (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C01B / ;
U.S. Cl.
CPC ...
423344 ;
Abstract
An improved process of preparing silicon nitride by the direct nitridation of silicon metal is disclosed. The process is a multi-step one which is substantially more efficient than prior processes and produces a silicon nitride having an oxygen content of less than 1%, a silicon metal content of less than 0.5%, and an alpha phase content of at least 85%, preferably at least 90%. The silicon nitride may be converted to a powder.