Combustion synthesis of TiC-metal composites and related plasma spraying deposition

The synthesis of titanium carbide/metal (i.e. Fe, Ti) composites from elemental powders by means of combustion reactions is investigated. A combustion booster (i.e. Teflon) to guarantee the self-propagating character of the combustion reaction is taken into account in the case of the TiC/Ti system. The combustion temperature and velocity of propagating front are found to decrease as the amount of metal in the starting mixture increase while both parameters increase as the amount of booster added to the mixture is augmented. The final products result constituted by titanium carbide and metal, being the latter one found as binder distributed around the carbide grains. In particular, a strong dependence of the grains size of the obtained titanium carbide on the iron content is observed. Moreover, the amount of titanium in the final product decreases as the Teflon content is increased, thus demonstrating that the latter one directly participates to the carburisation process. Subsequently, the TiC/Fe composite, once reduced in powder form, is tested as promising candidate for thermal spraying coatings. Results obtained by vacuum plasma spraying coatings are also reported.