B deficiency in TiB2 and B solid solution in TiN in TiN–TiB2 composites prepared by spark plasma sintering

Dense TiN–TiB2 composites were prepared by spark plasma sintering at 2573 K using TiN and TiB2 powders. With increasing TiN content from 60 to 90 vol%, the c-axis length of TiB2 in the TiN–TiB2 composites decreased from the stoichiometric value (0.3230 nm) to 0.3227 nm because of B deficiency in TiB2, whereas the a-axis length of TiB2 was unchanged from the stoichiometric value of 0.3031 nm. The lattice parameter of TiN increased from the stoichiometric value (0.4243 nm) to 0.4250 nm with increasing TiB2 content from 0 to 60 vol% because of B solid solution in TiN.