The effect of B4C on the microstructure and thermo-mechanical properties of HfB2-based ceramics

The fully dense HfB2–SiC composites with B4C addition were hot-pressed at 1850 °C. The effects of B4C on densification behavior and thermo-mechanical properties were investigated and compared with B4C free composite. Results indicated that B4C greatly enhanced the sinterability and refined grains. The highest increase on flexural strength and fracture toughness at room temperature were about 62% and 64%, respectively and the thermal conductivity slightly decreased by the addition of B4C.