Rod-like eutectic structure of arc-melted TiB2–TiCxN1−x composite

TiB2–TiCxN1−x composites were synthesized by arc-melting mixtures of TiB2, TiC and TiN powders in a N2 atmosphere at 60 kPa. TiB2–TiCxN1−x composites were obtained at TiN contents below 20 mol%, whereas TiB formed in the composites at higher TiN contents. TiB2–TiCxN1−x composites with a nominal composition of 36TiB2–44TiC–20TiN (mol%) had a rod-like eutectic structure, where the TiCxN1−x single-crystal rods dispersed in the TiB2 single-crystal matrix. The crystal orientation relationship between the TiB2 matrix and the TiCxN1−x rods was TiB2 (0 0 0 1)//TiCxN1−x (1 1 1). Vickers hardness (Hv) of the rod-like eutectic composite was 22.5 GPa.