Improved high-temperature mechanical property of carbon-phenolic composites by introducing titanium diboride particles

The effect of TiB2 on the thermal stability of phenolic and the role of TiB2 on the high-temperature mechanical property of carbon-phenolic composites are investigated by introducing TiB2 particles into phenolic, and then TiB2 particles into carbon-phenolic composites. The results show that the thermal stability of phenolic is enhanced by TiB2 additions. And the enhancement in thermal stability of phenolic exhibits a positive effect on improving the high-temperature mechanical property of carbon-phenolic composites. The flexural strength at 1000 °C of carbon-phenolic composites is increased by 148.2% after introducing 20 wt% TiB2 particles into phenolic matrix. In the heating stage before high-temperature mechanical test, TiB2 particles react with oxygen or oxygen-containing molecules released by phenolic pyrolysis. Therefore, amorphous carbon coated with glassy B2O3 and ceramic particles forms a new compact matrix. The well-bonded interface provides TiB2 modified carbon-phenolic improved mechanical performance at high temperature.