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. 28, 1997
Filed:
Sep. 11, 1996
Holger H Streckert, San Diego, CA (US);
Kirk P Norton, San Diego, CA (US);
Clement P Wong, San Diego, CA (US);
General Atomics, San Diego, CA (US);
Abstract
Methods for making hermetic silicon carbide matrix composite structures by CVI. A fibrous preform is created by winding strands of yarn of refractory fiber material helically about a graphite mandrel. Impregnation of the preform is carried out in a subatmospheric pressure zone at a pressure of about 700 Pa or less by maintaining a relatively slow flow of a mixture of helium and an alkyl chlorosilane through a coating zone heated to a temperature of between about 1100.degree. to 1200.degree. C. at a rate between about 2 and about 10 times the diffusion rate of the gaseous atmosphere in the fibrous preform. Coating is continued until silicon carbide impregnates the interstices of the fibrous preform and preferably deposits an outer layer of dense pore-free silicon carbide thereupon. The resultant structures are hermetic and provide leak-free containment of gases such as helium at temperatures of as high as 1,000.degree. C. and a pressure differential as high as about 20 MPa.