Effect of P2O5 addition on anorthite based glass-ceramic glazes

Abstract

Anorthite-based glazes are highly valued in the ceramics industry for their ease of crystallization under fast-firing conditions and their ability to impart excellent mechanical and aesthetic properties. This study investigates the effects of P2O5 on the thermal properties, microstructure, microhardness, and optical characteristics of anorthite-based glazes. The results indicate that the addition of P2O5 led to a reduction in both the glass transition temperature and crystallization temperature of the glazes. Furthermore, the increased intensity of the exothermic peak associated with crystallization suggests a greater amount of crystal formation in the P2O5-added glazes. In all compositions, anorthite was identified as the dominant phase. Moreover, an increased P2O5 content resulted in a higher number of anorthite crystals, while concurrently reducing their size. Glazes with P2O5 addition exhibited higher hardness values compared to those without P2O5. This outcome is attributed to the enhanced crystallization of the anorthite phase, as confirmed by DTA, XRD, and SEM analyses.