In situ reaction synthesis of Ti-TiB composites containing high volume fraction of TiB by spark plasma sintering process

The in situ toughened Ti-TiB ceramic-matrix composites containing high volume fraction of TiB were synthesized by spark plasma sintering technique under a pressure of 50 MPa, with sintering temperature ranging from 1100 degrees C to 1400 degrees C and heating rate of 150 degrees C/min, using Ti and TiB(2) powders. Results indicated that Ti-TiB composites sintered at 1400 degrees C provided the optimal combination of dense microstructure, well developed lath-shaped TiB grains, and excellent mechanical properties, including the relative density of 99.6%, bending strength of 608 MPa, and a rather high fracture toughness of 9.35 MPa m(1/2). Moreover, the micro-hardness of the composites reaches a relatively high level (18.3 GPa). (C) 2010 Elsevier B.V. All rights reserved.