Cordierite crystallization from stoichiometric gel and glass. Comparative study

The influence of precursor, gel and glass, on cordierite crystallization ha s been studied in the system MgO . Al2O3. SiO2. Also is compared the effect of superficial or bulk-crystallization, in powder or monolithic glass, on the sequence of crystallized pha ses and their microstructural evolution. A fter the same temperature treatment, the crystalline phases were analysed b y X-ray Diffraction (DRX) and Field Emission Scanning Electron Microscopy ( FESEM), where it seams clear that the final morphology of hexagonal cordier ite agrees hexagonal prisms with 5-10 mu m of external radius and variable length. Only the glass-derived cordierite has shown secondary phases, as mu llite and enstatite, what were stable for all studied temperatures.