Effects of TiC particle size on microstructures and mechanical properties of B4C–TiB2 composites prepared by reactive hot-press sintering of TiC–B mixtures

Abstract

Effects of the starting TiC particle size on the phase compositions, microstructures and mechanical properties of B4C–TiB2 composites prepared by reactive hot-press sintering of TiC–B mixtures were investigated. B4C–TiB2 composites were prepared from a single grade amorphous B powder (0.9 μm) and three different TiC powders (50 nm, 0.8 μm and 3.0 μm), respectively. The composites prepared from 50 nm and 3.0 μm TiC powders exhibited finer microstructures and higher hardness (29–30 GPa). The composite prepared from 0.8 μm TiC powder showed the coarsest microstructure but possessed the highest strength of 659 MPa due to its homogenous phase distribution without C impurity and abnormal grain growth that presented in the other two composites. The results indicated that the mechanical properties of B4C–TiB2 composite could be controlled by the particle size matching between TiC and B powders.