摘要 : Crystallization kinetics of amorphous alumina-zirconia-silica ceramics was studied by nonisothermal differential scanning calorimetry (DSC). Different amorphous materials were produced by plasma spraying of near-eutectic Al_2O_3-Z... 展开 Crystallization kinetics of amorphous alumina-zirconia-silica ceramics was studied by nonisothermal differential scanning calorimetry (DSC). Different amorphous materials were produced by plasma spraying of near-eutectic Al_2O_3-ZrO_2-SiO_2 mixtures. Phase composition and microstruc-ture of the amorphous materials and nanocrystalline products were analyzed. All of the investigated materials show an exothermic peak between 940 and 990 deg C in the DSC experiments. The activation energies calculated from DSC traces decrease with increasing SiO_2 concentration. Values of the Avrami coefficients together with results of the microstructural observations indicate that tetragonal zirconia crystallization from materials containing more than 10wt.% SiO_2 proceeds by a diffusion-controlled mechanism with nucleation occurring predominantly at the beginning of the process. In contrast, material with almost no SiO_2 exhibited a value of the Avrami exponent consistent with the crystal growth governed by processes at the phase boundary. 收起