Preparation of glass-ceramic glazes for fast firing applications by CaF2 substitution with B2O3 in the CaO-CaF2-Al2O3-SiO2 system

The present work aims to obtain glass-ceramic glazes for floor tile applications. In this regard, CaF2 was gradually replaced by B2O3 in the glass compositions belonging to the CaO-CaF2-Al2O3-SiO2 system. This substitution led to a noticeable decrease of crystallization peak temperatures and to an alteration of the crystallization trend. In the B2O3 bearing glazes, anorthite and gehlenite were identified as the major and minor crystalline phases, respectively. During concurrent crystallization and sintering based on the fast firing program, glass-ceramic glazes containing 9 weight parts of fluorine and 12 weight parts of boron oxide showed the most desirable sinterability. The optimized glass-ceramic glazes offered acceptable micro-hardness, whiteness and thermal expansion behavior after fast firing heat treatment.