Formation of silicon carbide whiskers and their microstructure

Abstract

Thermodynamic and kinetic conditions for the formation of SiC whiskers are established. The mechanism of their nucleation and growth are studied and, on this basis, the magnitude of the thermally activated barrier is determined from the rate of reduction data. The microstructures of whiskers are analysed and the role of interfacial tension between the nuclei and impurities, and the metallic iron catalyst is studied in relation to the formation of SiC whiskers. A possible reason for polytypism in SiC whiskers is also proposed.