CRYSTALLISATION KINETICS OF AMORPHOUS A CERAMICS

The crystallisation kinetics of amorphous ilica ceramics were studied by nonisothermal DSC. amorphous materials were produced by plasma of near -eutectic Al2O3-ZrO2-SiO2 mixtures. The composition an d microstructure of the amorphous and nanocrystall ine products were analysed. All the investigated m...

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Bibliographic Details
Published in:Journal of the European Ceramic Society 2009-12, Vol.29 (15), p.3159-3165
Main Authors: Chraska, T, Hostomsky, J, Klementova, M, Dubsky, J
Format: Article
Language:English
Online Access:Get full text
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Summary:The crystallisation kinetics of amorphous ilica ceramics were studied by nonisothermal DSC. amorphous materials were produced by plasma of near -eutectic Al2O3-ZrO2-SiO2 mixtures. The composition an d microstructure of the amorphous and nanocrystall ine products were analysed. All the investigated material s showed an exothermic between 940 and 990 C. The activ ation energies from DSC traces decreased with inc reasing SiO2 The values of the Avrami coeffic ients together results of the microstructural observati ons that tetragonal zirconia crystallisation from containing more than 10 wt% SiO2 proceeded by a ffusion-controlled mechanism with nucleation predo minantly at the beginning of the process. contrast, mater ial with almost no SiO2 exhibited value of the Avrami expo nent consistent with the growth governed by processe s at the phase
ISSN:0955-2219