Synthesis of TiB2-TiC composites by the solid-state reaction between B4C and Ti powders

The mechanism of solid-state reaction between B4C and Ti powders has been examined in the temperature range between 1000 °C and 1300 °C. In the early stage of the reaction, TiB and nonstoichiometric TiC0.58 in equilibrium with C-saturated Ti were formed from B4C and Ti; then TiB2 and TiCx containing higher amounts of C were formed from TiB, TiC0.58 and remaining B4C until the reaction ceased at an x-value of 0.69. This reaction path was not changed basically in the temperature range examined although the reaction rate was increased with temperature. Every product grain consisted of a TiCx core and a TiB2 layer around the core. This suggests that B hardly migrates in products and the reaction proceeds mainly by inward C diffusion and outward Ti diffusion through the products.