Method of preparing whiskers of silicon carbide and other materials

Abstract

Abstract A method of producing whiskers of silicon carbide and other materials. For the formation of silicon carbide, the method involves forming a first reaction zone containing microfine particles of silicon dioxide uniformly mixed with carbon or a carbon precursor, with the ratio of the silicon dioxide to the carbon present as a starting material or derivable from the precursor being greater than about 5 to 1 by weight. A closely adjacent second reaction zone is formed containing a porous fibrous mass of active carbon or an infusible carbon precursor. The reaction zones are heated under a non-oxidizing atmosphere to temperatures at which silicon monoxide is formed in the first reaction zone, diffuses to the second reaction zone and reacts with carbon derived from the carbon precursor in the second reaction zone to form silicon carbide whiskers. A continuous supply of a whisker-forming catalyst is provided in the second reaction zone, at least in the vicinity where the silicon monoxide and carbon react with each other. This can be assured, for example, by providing the whisker-forming catalyst in the first reaction zone together with a catalyst volatilizing aid which enables the catalyst to diffuse to the second reaction zone along with the SiO. The first reaction zone may also contain a catalyst for the SiO producting reaction. By changing the starting materials, reaction temperatures etc. but using the same method steps, whiskers of other materials such as AlN, sialons, Si 3l N 4 l etc. can also be prepared.

Inventors

• 👤 Sadashiv K. Nadkarni
• 👤 Mukesh K. Jain

Bibliographic Details