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:
Jan. 12, 1982
Filed:
Mar. 25, 1977
James C Uy, Farmington Hills, MI (US);
Andre Ezis, Grosse Ile, MI (US);
Ford Motor Company, Dearborn, MI (US);
Abstract
A method of making a silicon nitride part is disclosed. In this method an article of silicon nitride is first made which has a density less than the theoretical density of silicon nitride. This article also contains a densification aid. The entire surface area of this article is coated with a thin silicon nitride skin which is gas impervious. The so coated article is heated to a temperature for a time sufficient so that some of the densification aid may diffuse into the silicon nitride skin. The so treated article is then subjected to a pressure sufficiently high, for a time sufficiently long and at a temperature which permits the silicon nitride article and skin thereon to be compacted to increase the density of the article to a density greater than it originally had and to form the silicon nitride skin about the article so that the skin becomes an integral of the finished part.