Effect of impurity in starting kaolin materials on sintering behavior of cordierite ceramics

Effect of impurities in kaolin materials on the sintering behavior of the c ordierite ceramics was studied, Three kinds of kaolins were used, that is, Georgia kaolin, Chinese kaolin and New Zealand kaolin. Georgia kaolin witho ut alpha-quartz and cristobalite only gave a dense sintered body, alpha-qua rtz contained in both Chinese kaolin and New Zealand kaolin would retard th e densification of sintered bodies, In the case of Chinese kaolin, chemical components except for MgO, Al2O3 and SiO2 in mixture accelerated the gener ation of liquid phase at above 1300 degrees C and apparent porosity in sint ered body decreased by liquid phase sintering. In the case of New Zealand k aolin, cristobalite and alpha-cordierite crystallized at higher temperature than that of Georgia kaolin and Chinese kaolin.