SHI Xiaotao 1, ZHANG Ting 1, LU Zihan 1, SUN Qian 2, WU Jianqing 2, FAN Xueyun 3, FANG Hao 3
(1. Shanghai University of Engineering Science, Shanghai 201620, China; 2. South China University of Technology,Guangzhou 510640, Guangdong, China; 3. Jingdezhen Ceramic University, Jingdezhen 333403, Jiangxi, China)
Abstract: The traditional ferro-safflower glaze was prepared by adjusting SiO2/Al2O3 ratio. The composition was adopted according to the “aluminum silicon performance diagram”. Quality of the glaze could also be optimized by adjusting the firing temperature. Typical local areas of the samples were characterized by using X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray fluorescence (XRF). It is found that the SiO2/Al2O3 ratio has a significant effect on appearance of the glaze. When the SiO2/Al2O3 ratio is 8.6, the glaze shows promising "red spots" effect, varying in the order of"no spot” → “small spots” → “big spots” → “piece", as the temperature is changed from 1120 ℃ to 920 ℃. Hematite crystals precipitated on surface of the glaze. The content of Fe in different color spots varies greatly, with values of 6.86 wt.%, 27.68 wt.% and 17.95 wt.% from the inside, middle and outside areas, respectively.
Key words: ferro-safflower glaze; phase separation; crystallization; microstructure