Effects of Na_2O/K_2O Ratio on the Deformation Behaviour of the Floor Tile Bodies

摘要

Floor tile bodies have excellent technical characteristics particularly as regards mechanical properties and frost resistance. Besides of these properties they could not have any deformation during firing. Considering floor tiles are generally fired in roller kilns, tiles are moving along the kiln carried by the rollers. It is possible that tiles can be bended by the roller movement because it is submitted to vertical forces due to its own weight. Pyroplastic deformation is the bending of a ceramic specimen caused by gravity during heat treatment. It can be defined as deformation or the loss of a shape of a product during its firing. Deformation behaviour of the tiles is related to liquid phases formed during firing or to a reduced viscosity of these phases. In this study, effects of altering SiO_2/Al_2O_3 ratio and Na_2O/K_2O ratio of the tile composition on the deformation behaviour of the floor tiles. Correlations between compositional change and deformation behaviour of the tile bodies will be also discussed in this presentation.