Rod-like eutectic structure of arc-melted TiB2–TiC N1− composite

Abstract

Abstract TiB 2 –TiC x N 1− x composites were synthesized by arc-melting mixtures of TiB 2 , TiC and TiN powders in a N 2 atmosphere at 60 kPa. TiB 2 –TiC x N 1− x composites were obtained at TiN contents below 20 mol%, whereas TiB formed in the composites at higher TiN contents. TiB 2 –TiC x N 1− x composites with a nominal composition of 36TiB 2 –44TiC–20TiN (mol%) had a rod-like eutectic structure, where the TiC x N 1− x single-crystal rods dispersed in the TiB 2 single-crystal matrix. The crystal orientation relationship between the TiB 2 matrix and the TiC x N 1− x rods was TiB 2 (0 0 0 1)//TiC x N 1− x (1 1 1). Vickers hardness ( H v ) of the rod-like eutectic composite was 22.5 GPa.