| Traditional ceramic products are made up of clay, quartz and feldspar raw materials. The technical properties of
these products depend on physico-chemical aspects of ingredient materials, their reaction kinetics during firing
and ultimate microstructure development. Irreversible dilatometry is an uncommon but powerful technique to
study the densification behaviour of ceramics. Differential coefficient of expansion (DCE) is the derivative of
percentage of linear change (PLC). DCE is taken as indicator of phase development and other thermal reactions.
One white burning and one red burning clay commonly used for manufacturing ceramic tile bodies were studied
for irreversible dilatometry. The dilatometric behaviour of individual clays and their combined effect on a ceramic
tile body were correlated. Red clay was found to be more thermally stable than white clay in 550o-650oC temperature
range because of lesser dimensional vibrations. DCE curves of experimental bodies illustrated that the bodies
were in the thermally induced dimensional vibration phases in the temperature ranges of 500o-650oC and
800o-1000oC, hence these regions are critical and taken care while designing firing schedule. The study showed
that the improved performance obtained by irreversible dilatometry can be utilized for designing compatible firing
schedule and to achieve better productivity.
[Keywords: Clay, Irreversible dilatometry, Ceramic tile, Firing schedule] |
