Effect of phosphorus on microstructure development in cordierite transparent glaze

The study aimed at assessing the effect of phosphorus on the microstructure development of cordierite transparent glaze. Crystallization path of glaze was investigated by X-ray diffractometry (XRD), whereas microstructure development was determined by scanning electron microscopy (SEM). Results suggested the addition of phosphorus to reduce the melting temperature of spodumene and anorthite by 150 degrees C and 180 degrees C respectively, and to widen the existence temperature of cordierite by 40 degrees C where cordierite was detected as the only phase. In addition, phosphorus addition decreased the high temperature viscosity, thus making cordierite more easily to assemble and crystallize on the glaze surface.