Matrix structure evolution and thermo-mechanical properties of carbon fiber-reinforced Al2O3SiCC castable composites

Abstract The spalling and corrosion during the thermal cycles are the main causes of the damages observed in Al 2 O 3 SiC C castable composites that are used in molten-iron system. Using the catalyst of nano Ni and ball pitch in the matrix, Al 2 O 3 SiC C castable composites were prepared with the anti-oxidant addition of silicon. The results indicate that the high temperature of the Al 2 O 3 SiC C castable composites can be increased by above 42%, and the thermal shock resistance can be enhanced by above 20% because the ball pitch is carbonized and releases C x H y vapor, which can be pyrolized to carbon atoms and subsequently deposited into carbon fibers under the catalyst action. The starting temperature of carbon fiber growth is approximately 900 °C, and their diameter and aspect ratio can increase with the rising temperature. The in-situ generation of carbon fibers in Al 2 O 3 SiC C castable composites can significantly improve the fibers’ thermo-mechanical properties.