Crystallization behavior in the glass system MgO–Al2O3–SiO2: influence of CeO2 addition
| Autor: | Sung-Bum Sohn, Se-Young Choi |
|---|---|
| Rok vydání: | 2001 |
| Předmět: |
Materials science
Nucleation Analytical chemistry Mineralogy Crystal growth Condensed Matter Physics Microstructure Isothermal process Electronic Optical and Magnetic Materials law.invention Crystal law Differential thermal analysis Materials Chemistry Ceramics and Composites Crystallization Glass transition |
| Zdroj: | Journal of Non-Crystalline Solids. 282:221-227 |
| ISSN: | 0022-3093 |
| DOI: | 10.1016/s0022-3093(01)00344-1 |
| Popis: | For the investigation of the crystallization behavior of the glass with the composition 2MgO–2Al2O3–5SiO2, corresponding to stoichiometric cordierite, according to the addition of CeO2 as a flux, the maximum nucleation and crystal growth rates were determined by observing the microstructure of the crystallized glass with scanning electron microscopy (SEM). The crystallization mechanism was also studied by an isothermal method using differential thermal analysis (DTA). The glass transition temperature (Tg) decreased with the CeO2 addition and only α-cordierite was precipitated as a main crystal phase without μ-cordierite for all heat treated glasses containing CeO2. The maximum nucleation and crystal growth rates were 2.4 μm −3 h −1 at 800°C and 0.3 μm h −1 at 915°C, respectively. The activation energy value E obtained from isothermal method was 88.9±9.1 kcal mol −1 , and the Avrami constant n was 1.08±0.27, which indicates a surface growth mechanism through an interface reaction. |
| Databáze: | OpenAIRE |
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