Microstructure of TiB2/B4C Composites with 1% Y2O3 Prepared by Co-Precipitating and in Situ Synthesis

TiB2/B4C composite with a TiB2/B4C mass ratio of 40/60, and with 1% Y2O3 was fabricated by using powders co-precipitated from TiCl4 solution and B4C powder. The microstructures of TiB2/B4C ceramic composites fabricated under different sintering temperatures were studied by microscope, SEM and TEM. The results showed that the composite was composed of B4C phase and TiB2 phase, with the B4C being the matrix and TiB2 the secondary phase. The size of TiB2 particles was in a range of 1 × 6 μm, with an average particle size of about 3.1 μm. The size of TiB2 particles increased with increasing sintering temperature. Twins were found in B4C crystal. The size of inter-granular and intra-granular TiB2 particles was 300 and 80 nm, respectively.