Kinetics of Specific Surface Area Change Using the Boltzmann Model

摘要

During sintering of the 2MgO-2Al_2O_3-5SiO_2 system, cordierite, an attractiveceramic material because of its properties, is obtained. Effects of mechanochemicalactivation of stoichiometric mixtures, performed to investigate possibilities of loweringcordierite formation temperature during sintering, were monitored by thermogravimetricand differential thermal analyses. Specific surface areas of the mechanically activatedpowder mixtures were determined by the BET method. Kinetics of the specific surface areaincrease was analyzed using the Boltzmann model. It was confirmed that with activation timeincrease, temperatures of phase transformations were shifted to lower values and, accordingto FTIR analysis no significant changes occurred during material aging. According to theobtained results, it may be concluded that since mechanochemical activation has aninfluence on the treated powder mixture, lowering of the cordierite formation temperatureduring the sintering process is expected.