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:
Jul. 04, 1989
Filed:
Mar. 04, 1988
John J Rogers, Baton Rouge, LA (US);
John Semen, Baton Rouge, LA (US);
Ethyl Corporation, Richmond, VA (US);
Abstract
The strength of SiC ceramic parts derived from certain preceramic compositions is improved by (A) cooling the parts in an inert atmosphere to a temperature at least as low as about 800.degree. C. after preparing them by molding and pyrolyzing the preceramic compositions, (B) then heating them in air to about 1200.degree.-1300.degree. C., and (C) keeping them in air at that temperature for at least about one hour before allowing them to cool. The preceramic compositions from which the ceramics are derived are mixtures of SiC powders and polysilazanes having an alkali metal content of 0-100 ppm and prepared by reacting an organodihalosilane with ammonia, treating the ammonolysis product with a basic catalyst which is capable of deprotonating an NH group that is adjacent to an SiH group, and quenching the resultant product with an electrophilic quenching reagent.