Rod-like eutectic structure of arc-melted TiB_2-TiC_xN_(1-x) composite

摘要

TiB_2-TiC_xN_(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_xN_(1-x) composites were obtained at TiN contents below 20 mol%, whereas TiB formed in the composites at higher TiN contents. TiB_2-TiC_xN_(1-x) composites with a nominal composition of 36TiB_2-44TiC-20TiN (mol%) had a rod-like eutectic structure, where the TiC_xN_(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_xN_(1-x) rods was TiB_2 (0001 )//TiC_xN_(1-x) (111). Vickers hardness (H_v) of the rod-like eutectic composite was 22.5 GPa.