Molten Salt Synthesis and Characterization of Titanium Carbide-Coated Graphite Flakes for Refractory Castable Applications

Titanium carbide (TiC)-coated graphite flakes were prepared using the low-temperature molten salt synthesis technique. Titanium (Ti) particles were mixed with graphite in a mass ratio (Ti/C) between 1/5 and 3/5, and reacted in alkali chloride salts at 650-950 degrees C for 4-8 h. The TiC formation reaction was complete in KCl or the KCl-LiCl eutectic salt after 8 h at 850 degrees C, but not in LiCl or NaCl, indicating that the former were more effective than the latter in accelerating the TiC coating formation. Although various Ti/C ratios were used, the TiC formation reaction was complete in all samples heated for 4 h at 950 degrees C, indicating that the amounts/thickness of TiC coatings could be readily tailored for future castable applications. TiC coatings prepared in KCl or the KCl-LiCl eutectic salt (after 4 h at 950 degrees C or 8 h at 850 degrees C) were of high quality: crack free, homogeneous, and comprising nanosized TiC particles. The coating synthesis process is believed to be dominated by the template-growth mechanism.