Journal of the American Ceramic Society, Vol.102, No.1, 63-69, 2019
Formation mechanism of a wrinkled and textured Al2O3-ZrO2 nanoeutectic rapidly solidified from oxy-acetylene flame remelting
A highly wrinkled and textured Al2O3-ZrO2 nanoeutectic induced by oxy-acetylene flame remelting was elaborated for the first time from the perspective of morphological evolution and formation mechanism. The rapidly solidified Al2O3-ZrO2 ceramic exhibits a wrinkled cellular nanoeutectic structure with a minimum interphase spacing of 0.12 mu m. The Jackson-Hunt (JH) eutectic theory is more appropriate to predict the growth of Al2O3-ZrO2 nanoeutectic induced by oxy-acetylene flame remelting than the Trivedi-Magnin-Kurz (TMK) model. The bulk growth rate of 7.8 mu m(3)/s is close to the theoretically predicted value of 11.0 mu m(3)/s by the JH model. The eutectic growth rates of Al2O3-ZrO2 with average interphase spacings of 0.12 and 0.3 mu m are estimated to be 763.8 and 122.2 mu m/s, respectively. Especially, a mesoscopic insight into formation mechanism of the wrinkled and textured eutectic was proposed from a three-dimensional perspective based on both the crystal growth orientation and the airflow effect.