B₄CとTi粉体間の固相反応によるTiB₂-TiC複合体の合成

抄録

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 TiC_0.58 in equilibrium with C-saturated Ti were formed from B₄C and Ti; then TiB₂ and TiC_x containing higher amounts of C were formed from TiB, TiC_0.58 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 TiC_x 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.