The effect of BN addition on thermal shock behavior of fiber reinforced porous ceramic composite

Fiber reinforced ceramic composite (mullite fiber/α-Al2O3 powder) was produced by the organic flocculating method. Air-quenching was employed to determine the drop in bending strength of the composite after thermal shock, and the critical temperature of the composites with different fiber contents. The thermal shock behavior was found to improve significantly by the addition of 3% hexagonal boron nitride (H-BN). The critical temperature reached up to 1000 °C, compared to 500 °C without presence of BN. The mechanism was investigated through a relative experiment and XRD study.