PRECURSOR MORPHOLOGY EFFECTS IN COMBUSTION-SYNTHESIZED AND DYNAMICALLY CONSOLIDATED TITANIUM CARBIDE AND TITANIUM BORIDE

The combustion synthesis/dynamic consolidation (CS/DC) technique was applied to titanium-carbon and titanium-boron mixtures with different initial precursor carbon and boron powder morphologies. The evolution of the CS/DC product structure was investigated by analyzing and comparing the combustion synthesis products following three fabrication process steps: reacted loose powders, reacted green compacts, and reacted green compacts which were dynamically consolidated shortly after the synthesis. In all cases, the purity of the precursor carbon and boron powders was found to affect the residual porosity of the products. However, the dependence of the resultant product grain morphology on the morphology of the precursors was not as straightforward. Correlations between the respective product structures and possible reaction mechanisms are discussed.