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:
Apr. 07, 1992
Filed:
Aug. 20, 1986
Juris Verzemnieks, Tacoma, WA (US);
Fredrick H Simpson, Seattle, WA (US);
Abstract
A monolithic silicon nitride radome structure having a forward portion, an after portion and a transition portion therebetween, is provided. The forward portion has a density of about 0.75 to 1.0 g/cc, the after portion has a density of about 1.6 to 2.0 g/cc and the transition portion has regions of increasing density, from forward to aft, each region having a greater density than the preceding portion or region. Also provided is a method for manufacturing the above-described radome structure which comprises filling and compacting a series of formulations consisting essentially of particulate silicon, silicon nitride and a fugitive pore-forming material into a radome mold, removing the shaped compact from the mold, subliming the pore-forming material from the compact to form a porous compact structure, and reacting the porous structure with nitrogen to convert the porous structure to an identically shaped radome structure of .alpha.-silicon nitride whiskers.