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. 17, 1978
Filed:
Mar. 31, 1976
Francis H Dulin, Oakland Township, Oakland County, MI (US);
Champion Spark Plug Company, Toledo, OH (US);
Abstract
A fired, electrically semi-conducting ceramic body is disclosed. The body consists essentially of silicon carbide particles having a median particle size from about 3 to about 25 microns dispersed in a bonding matrix. The silicon carbide particles constitute from about 50 to about 70 percent of the body. The body has an 'apparent porosity' as subsequently defined herein from 20 to 40. The production of such a body from a batch composed of silicon carbide, alumina, silica and at least one oxide, carbonate or hydroxide of calcium, magnesium, barium or strontium is also disclosed. The batch is milled and pressed into a shape, and the resulting shape is then fired in an inert gas atmosphere to a temperature from about 2,300.degree. to 2,800.degree. F. for a time sufficiently long to produce a semi-conductor body having the requisite apparent porosity of from 20 to 40 percent.