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. 10, 1989
Filed:
Dec. 15, 1988
Samuel C Weaver, Knoxville, TN (US);
Richard D Nixdorf, Knoxville, TN (US);
American Matrix, Inc., Knoxville, TN (US);
Abstract
A method for achieving a high yield of beta silicon carbide whiskers. According to this method, very small (e.g., 0.002 microns) fluffy silicon dioxide particles having a very large surface area (e.g., 200 m.sup.2 /g) are mixed with a fluffy carbonized material. These materials have a void volume of about 40 percent or greater. The silicon dioixde is present in an amount by weight approximately twice that of the carbon constituent. This mixture is heated, preferably in the presence of a catalyst (e.g., anhydrous boric oxide and powdered aluminum metal) at a temperature of about 1650.degree..+-.300.degree. C. for a time of one-half to four hours. During this heating the gaseous reaction products are maintained at a steady state as with a low flow of argon gas through the furnace. The resultant SiC whiskers have a diameter in the range of about 0.5 to 10 micrometers, and a length of about 10 to about 1000 micrometers. These SiC whiskers are principally beta phase silicon carbide and the whiskers have a smooth surface morphology. The effects of the variables are described.