EFFECT OF ALUMINUM ADDITION ON THE COMBUSTION REACTION OF TITANIUM AND CARBON TO FORM TIC

Aluminium was incorporated into the reactant mixture with a molar ratio of Ti/C of 1.0 to study the effect of its addition on the combustion reaction between titanium and carbon to form TiC. Thermal analysis of the reactant mixture and component analysis of the reaction product suggest that the combustion reaction of the Ti-C-Al system proceeds in such a way that aluminium initially reacts with titanium to form titanium aluminide compounds of TiAl3, Ti2Al, and TiAl with heat evolution, and then the reaction between titanium and carbon and the decomposition of titanium aluminide to titanium and aluminium is subsequently followed. As the amount of aluminium incorporated was increased over the range of 0 to 40 wt%, the grain size of TiC decreased from approximately 15 mum to 0.4 mum. It was also observed that most of the aluminium in the TiC-Al composite was distributed on the surface of the spherical TiC grain.