Microstructural evolution and oxidation behavior of TiB2SiCB4C composite fabricated by reactive spark plasma sintering

Abstract Microstructural evolution and oxidation behavior of TiB 2 SiC B 4 C composite fabricated from Ti SiC B 4 C system with different weight ratios via reactive SPS were investigated in detail. Based on the characterizations of SEM, XRD, TEM and HRTEM, it was found that the solid diffusion induces reactions between Ti and B 4 C to form TiB 2 (TiB), C and Ti(B,C,Si). Afterwards, the results of oxidation tests at 800 °C, 900 °C and 1000 °C demonstrated that the sample with highest TiB 2 contents performed the best oxidation resistance due to the lowest porosity. Furthermore, the smoothly glassy oxidation layer above substrate composed of TiO 2 and B 2 O 3 became thicker with temperature increasing, meanwhile, the vaporized B 2 O 3 recrystallized into plate-like, rose-like even large-monolithic grains.