초록 ▼

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 m2/g) are mixed with a fluffy carbonized material. These materials have a void volume of about

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 m2/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°±300°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.

대표청구항 ▼

A method for producing a high yield of silicon carbide whiskers having diameters of about 0.5 to about 10 micrometers and lengths of about 10 to about 1000 micrometers, which comprises: preparing a mixture of silicon dioxide particles and carbon fibers, said silicon dioxide particles having an avera

A method for producing a high yield of silicon carbide whiskers having diameters of about 0.5 to about 10 micrometers and lengths of about 10 to about 1000 micrometers, which comprises: preparing a mixture of silicon dioxide particles and carbon fibers, said silicon dioxide particles having an average diameter of about 5 to 15 millimicrons and an average surface area of about 200 to 400 square meters per gram, said silicon dioxide particles being about 1.5 to about 2.75 times, by weight, said carbon fibers and said silicon dioxide having a void volume of about 40 percent to about 98 percent; heating said mixture to a temperature of about 1600°to 1900°C. in a furnace for a time at least about 0.2 hours, followed by cooling to room temperature; and maintaining gaseous reaction products of reactions between said silicon dioxide and said carbon fibers at the surface of said mixture at a steady state condition during said heating by flowing a substantially inert gas through said furnace.