Synthesis reactions for Ti3SiC2 through pulse discharge sintering TiH2/Si/TiC powder mixture

Ternary compound Ti3SiC2 was rapidly synthesized by pulse discharge sintering the powder mixture of 1TiH(2)/1Si/1.8TiC without preliminary dehydrogenation. Almost single-phase dense Ti3SiC2 was synthesized at 1400 degrees C for 20 min. The grain size of synthesized Ti3SiC2 strongly depends on sintering temperature, The synthesis mechanism of Ti3SiC2 was revealed to be completed via the reactions among the intermediate phases of Ti5Si3, TiSi2 and the other reactants in the starting powder. The Ti-Si liquid reaction occurring above the Ti-Ti5Si3 eutectic temperature at 1330 degrees C was found to assist the synthesis reaction and densification of Ti3SiC2. The dehydrogenation of TiH2 was accelerated by the synthesis reactions. (C) 2007 Elsevier Ltd. All rights reserved.