Microstructural Characterization of Cordierite Ceramics Produced from Natural Raw Materials and Synthetic Powders

Abstract

Microstructures of cordierite ceramics produced from natural raw materials and synthetic powders were examined. Two batches to constitute the cordierite composition (2Al 2O3.2MgO.5SiO 2) were prepared from raw materials (kaolinite, sinter magnesite, talc and pyrophyllite) and pure synthetic powders (Al 2O3, MgO and SiO 2). These mixtures were milled in a planetary ball mill for 24 h, compacted using an unaxial press and sintered at 1350 o C for 1, 3 and 5 hours. Sintered bodies were characterized using X-ray diffraction (XRD), differential thermal analysis (DTA), optical microscopy and scanning electron microscopy (SEM). It was shown that the cordierite ceramics produced from natural raw materials had more developed and denser microstructure than those produced from synthetic powders.