Fig. 3 shows the XRD patterns of the SiC whisker, ZrO2 powder,flash-sintered composite, and conventionally sintered composite According to the XRD patterns, the SiC whisker is pure -SiC, while the ZrO2 powder contains the minor m-ZrO2 phase and major t-ZrO2 phase. The pattern of the flash-sintered composite reveals that the material contains all these three phases without any other detectable phase, suggesting that the sintering process did not damage any phase. Comparing the XRD patterns of the pure ZrO2 and the composite reveals that the relative intensity of the diffraction peaks corresponding to m-ZrO2 phase becomes weaker within the composite, indicating some of the m-ZrO2 transformed to t-ZrO2 during the sintering. On the other hand, besides the threemajor phase, the composite prepared by conventional sintering also contains detectable SiO2 phase, likely due to the oxidation of SiC whisker during air sintering. Therefore, flash-sintering can lead to pure SiCw/ZrO2 composite, which is difficult to obtain by conventional pressureless sintering in air. It is likely due to the extreme short sintering time in flash sintering.