Asymmetric temperature distribution during steady stage of flash sintering dense zirconia

Surface temperature of zirconia is measured during flash sintering using thermal imaging camera. The results reveal that in the steady stage the temperature along the longitude of electric field is uneven: the temperature at the end of gauge section close to the anode is much higher than that close to the cathode; and the highest temperature locates at the three-quarter of the length of gauge section from the cathode. We further demonstrate that the asymmetric temperature distribution is related to the flashing since temperature distribution in the specimen without flashing is symmetric. The possible mechanisms that resulted in the asymmetric distribution are discussed.