Microstructural evolution in the combustion synthesis of titanium carbide

Microstructural evolution in the combustion synthesis of titanium carbide was investigated using the combustion front quenching method and scanning electron microscopy. The results showed that the combustion reaction between titanium and carbon began with reaction diffusion of carbon into the surface layer of titanium powder, leading to the formation of a TiC shell around the titanium powder. The titanium powder coated with the TIC shell melted and became a molten core, as the carbon atoms diffused into the core through the TiC shell, TiC grains gradually crystallized. In the final products, the morphology and size of the initial titanium powder were maintained in the form of the TiC granule which was composed of isometrical TiC grains. In addition, a lamellar eutectic was present at the centre of some TiC granules. The microstructural evolution in the combustion synthesis of TiC has been described with a shell-core model.