PLASMA CHEMICAL SYNTHESIS OF FINE MoSi2 AND MoSi2-Si3N4 COMPOSITE POWDERS

Abstract

The preparation of fine MoSi2 and MoSi₂ - Si₃N₄ composite powders with specific surface area of 16-33 and 30-41 m²/g respectively by evaporation of Si and Mo raw powder mixtures or coarse grained MoSi₂ in radio frequency inductively coupled nitrogen plasma flow was investigated. Specific surface area of obtained powders as well as content of MoSi₂ modifications, Si₃N₄ and extra phases Mo₅Si₃, Si depend on the raw powder feeding rate, the cooling gas flow rate and the composition of raw mixtures. The shape of the product particles was spherical for MoSi₂ and both spherical and whiskers for composites.