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. 29, 1991
Filed:
Oct. 30, 1989
Craig A Willkens, Sterling, MA (US);
Normand D Corbin, Northboro, MA (US);
Brian J Caprera, Southbridge, MA (US);
Norton Company, Worcester, MA (US);
Abstract
A friable silicon nitride body is prepared by infiltrating a non-friable silicon nitride body with a fluid which expands upon freezing, rapidly freezing the fluid, and thawing the frozen fluid. Silicon nitride flakes and chunks obtained with only light pressure on the friable body may then be final milled to a desired particle size more rapidly and with less energy input than with conventionally processed silicon nitride. The silicon nitride body may have a higher density than has previously been used to prepare silicon nitride powders, thereby preventing the generation of potentially hazardous whiskers in the final powder product.