Enhanced resistance to thermal cycling of slag-containing vitrified porcelain tiles

Slag was progressively substituted upto 15 (w/w) % to feldspar in a normal porcelain composition and compacts prepared by the usual ceramic processing were sintered at 1100-1300 degrees C. The effect of thermal cycling on flexural strength of the vitrified samples was studied and the behaviour was correlated with phase and microstructural features. It was found that slag incorporation increased residual strength in thermally cycled samples compared to normal porcelain. The microstructural features of thermally cycled slag-containing porcelain showed limited quartz grain cracking compared to normal porcelain composition, which results in better strength. Formation of anorthite, which has low thermal expansion, in slag-bodies, is also significant in the development of better thermal stability.