Effect of iron and cobalt addition on TiC combustion synthesis

Fe and Co metals were incorporated into a Ti and C mixture with a molar ratio of 1.0 over the range of 0 to 40 wt. % to study their effect on TiC combustion synthesis. The addition brought about the grain size decrease, change of grain shape (angular to spherical), and different distribution (agglomerated to isolated) of TiC grains. Both Fe and Co additives were distributed around TiC grains and served as a binder. It was observed that reaction between Ti and C was kinetically more favorable than any other reactions in the Ti–C–Fe or Ti–C–Co system. Based on the activation energy from an Arrhenius plot of In[(1−w)^1/2u/T_c] vs 1/T_c, which was obtained by combustion temperature and wave velocity measurements, the reaction mechanism in combustion synthesis of TiC with the addition of 20 wt. % Fe and Co was suggested.