Synthesis and consolidation of TiN/TiB2 ceramic composites via reactive spark plasma sintering

The simultaneous synthesis and densification of TiN/TiB2 ceramic composites via reactive spark plasma sintering (RSPS) was investigated. Different component ratios (TiH2/BN (TiN, B)) and heating rates (112.5-300 degrees C/min) were used to initiate the chemical reaction for TiN/TiB2 synthesis. The omit RSPS process was revealed to have three stages, which are described separately. The relationships between the RSPS conditions, the microstructure and the properties of sintered ceramic composites were established. A Vickers hardness of 16-25 GPa and a fracture toughness of 4-6.5 MPa m(1/2) were measured for various compositions. Sintered ceramic composites containing 36 wt% TiB2 with the highest relative density of 97.4 +/- 0.4% and an average grain size of 150-550 nm have been obtained. (C) 2010 Elsevier B.V. All rights reserved.