Effect of Talc Grain Size on Microstructure of Cordierite Ceramics

The effect of talc grain size on the microstructure of cordierite ceramics prepared from the talc, kaolin and alumina was studied. Six kinds of talc materials with various grain size distributions were prepared by classification and grinding. Enstatite formed by decomposition of fine talc grains contributed to the cordierite formation at a lower temperature of 1200°C without transformation to protoenstatite. When the grain size of the talc was larger than that of kaolin, behavior of melt of the talc grains was so complicated that the melt affected the pore formation of fired bodies. By grinding the talc to submicron size, it was possible to densify the bodies at a temperature lower than that of cordierite formation, and high strength of fired bodies was achieved.