Comparison of physical and mechanical properties of cordierite based ceramics produced from natural raw materials and synthetic powders

Mechanical and physical properties of cordierite materials produced from natural raw materials and synthetic powders were investigated. Kaolinite, sinter magnesite, talc and pyrophyllite as natural raw materials and Al ₂O₃, MgO and SiO₂ as synthetic powders were used to obtain the synthetic cordierite. 6 different mixtures were prepared for the selected three target compositions in the Al₂O ₃-MgO-SiO₂ quaternary diagram. Each mixture was milled in a planetary ball mill followed by pressing in an unaxial press and sintering in an electrical furnace at 1350°C for 1, 3 and 5 hours. Sintered cordierite bodies were characterized using X-ray diffraction(XRD), Archimedes method and three point bending strength tests. It was shown that the cordierite ceramics produced from natural raw materials had denser structure, finer porosity, lower water absorption and better bending strength than those produced from synthetic powders.