PLASMA SYNTHESIS OF ULTRAFINE SIC/TIC-COMPOSITE POWDERS

The objective of the work presented in this paper is the thermal plasma production of nanoscaled SiC/TiC composite powders by vapor phase reactions of the tetrachlorides of silicon and titanium with ethylene. The investigations were done in an Ar/H₂ r.f. induction plasma at plate power of 30 kW and atmospheric pressure. Homogeneous composites can be generated in all compositions of interest for ceramic applications. Mean particle size is in the range of 10 - 50 nm. The composites are always crystallized in a high degree. Identified phases are TiC_x, 0,5 < x < 0,8, β-SiC and α-SiC. All crystalls are covered with an amorphous surface layer.