Journal of the American Ceramic Society, Vol.95, No.8, 2640-2646, 2012
Study of Phase Transformation and Microstructure in Sintering of Mechanically Activated Cordierite Precursors
A cordierite precursor mixture of talc, boehmite, and kaolin was studied with respect to the influence of dry milling intensity per unit time on phase transformation pathways and microstructural development. Three milling methods (ball, ring, and planetary) were used, and the effects of mechanical action and milling times were investigated at different temperatures. Sintering at 1000 degrees C for 2 similar to h resulted in the development of significant mechanically assisted phase transformations specifically related to formation of mullite in the most highly activated materials. Mullite transformation to precordierite mineralogy and the formation of magnesium aluminum silicate were also found to be dependent on the degrees and methods of mechanical processing. Planetary milling resulted in the highest densification of the material, which when sintered at 1300 degrees C for 2 similar to h produced a ceramic body rich in cordierite composition.