Lamellar ceramics of Ca$_{2}$SiO$_{4}$ prepared by mechanical activation of powders

Abstract

Stoichiometric mixtures of calcium carbonate and silicon oxide have been mechanically activated by milling during several hours (29 and~50) previous to the solid state reaction, in order to obtain dicalcium silicate, Ca$_{2}$SiO$_{4}$. X-ray powder diffraction and differential thermal analysis studies show that the mechanical processing of the powders induces changes in the orientational uniformity of crystallites and the diminution of the decomposition temperature of the calcium carbonate. Microlamellar particles of $\beta$-Ca$_{2}$SiO$_{4}$ were obtained when the solid state reaction was achieved at 1450$^\circ$C, whereas $\beta$-Ca$_{2}$SiO$_{4}$ and $\alpha$'$_{L}$ -Ca$_{2}$SiO$_{4}$ phases were obtained when the reaction took place at 1000$^\circ$C. By means of the powder processing described in this work, we can prepare phase $\beta$-Ca$_{2}$SiO$_{4}$ without any chemical stabilizer and with an unusual lamellar morphology.