PLASMA CHEMICAL SYNTHESIS OF FINE MoSi_(2) AND MoSi_(2)-Si_(3)N_(4) COMPOSITE POWDERS

摘要

The preparation of fine MoSi_(2) and MoSi_(2) - Si_(3)N_(4) composite powders with specific surface area of 16-33 and 30-41 m~(2)/g respectively by evaporation of Si and Mo raw powder mixtures or coarse grained MoSi_(2) in radio frequency inductively coupled nitrogen plasma flow was investigated. Specific surface area of obtained powders as well as content of MoSi_(2) modifications, Si_(3)N_(4) and extra phases Mo_(5)Si_(3), Si depends 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 MoSi_(2) and both spherical and whiskers for composites.