Preparation of micro-coiled TiC fibers by metal impurity-activated chemical vapor deposition

Micro-coiled TiC fibers have been directly prepared on a graphite substrate from TiCl4 + H2 + PCl3 gas mixtures at 1050°C by the Si + Pd mixed impurity-activated CVD process. It was found that the presence of small amounts of PCl3 in the source gas as well as Si + Pd mixed impurities were indispensable for the deposition of the micro-coiled TiC fibers. The obtained coiled TiC fibers were in a polycrystalline state with a 1–5 μm coil diameter and 20–150 μm coil length. The TiC coils were generally double coils similar to DNA.