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:
Aug. 10, 1976
Filed:
Oct. 10, 1972
Donald W Roy, Golden, CO (US);
Franklin J Stermole, Golden, CO (US);
Coors Porcelain Company, Golden, CO (US);
Abstract
The present invention provides a high heat resistant, light transmitting, thermal shock resistant and high strength sintered ceramic body containing at least about 98% by weight magnesia-alumina spinel and a method of manufacturing the same which comprises forming a uniform mixture containing approximately equal molar amounts of magnesia and alumina plus lithium fluoride in an amount of about 2% by weight of the mixture, the alumina in the mixture having an average particle size of less than 0.5 microns; calcining the mixture at such a temperature and under such conditions as will result in substantially less than total reaction to form spinel during calcining, i.e. less than 80% and preferably less than 50%; pressing the mixture into a self-sustaining compact having a density of at least about 2 grams per cubic centimeter; and then firing the compact, preferably in a wet hydrogen atmosphere, to a temperature of from about 1600.degree. to 1900.degree.C.