Synthesize Ti_3SiC_2 from TiH_2 by Pressureless Sintering

摘要

In this paper, titanium silicon carbide (Ti_3SiC_2) powders were synthesized from TiH_2 as Ti source by pressureless sintering in flowing argon atmosphere without preliminary dehydrogenation. Starting materials are powder mixtures with the mole ratio of 3TiH_2/Si/2C or 3TiH_2/SiC/C. Both kinds of starting materials were sintered in a tube furnace at the temperature range from 1300°C to 1500°C for 10～180min in flowing argon atmosphere. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to characterize the phase compositions and morphology of the products after different treatments. It was showed that almost single phase Ti_3SiC_2 powder (95 wt.%) can be synthesized by pressureless sintering from 3TiH_2/Si/2C powders at 1400～1425°C for about 180min or from 3TiH_2/SiC/C powders at 1425～1500°C for about 180min. From SEM micrographs, as-synthesized samples were porous. Most plate-like grains were about 5～10 μm in diameter and 1～2 μm in thickness.