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.