“南澳Ⅰ号”出水青花瓷的制作技术分析

Technological research on blue and white porcelain from the Nan’ao Ⅰ shipwreck

为了解"南澳Ⅰ号"出水青花瓷的产地、材料特征和制作工艺,对"南澳Ⅰ号"出水的6片外销青花瓷进行分析。元素成分结果显示,其中2片为景德镇所产,4片为漳州窑所产,两类外销青花瓷所用胎釉原料不同,但都采用了国产青花料;显微结构观察结果显示漳州窑所产外销青花瓷的工艺有别于景德镇青花瓷,景德镇青花色料集中于胎釉结合处而漳州青花色料在釉层中间或在釉层内扩散。对漳州窑青花进行OCT无损分析显示青花部分呈弥散状亮点,显示青花料散布于釉层中。仿烧青花瓷片样品的显微结构对比也显示这批出水漳州窑青花可能采用了不同于景德镇釉下青花的工艺技法。热膨胀分析表明出水的两类青花瓷烧成温度接近,分别为1 160℃与1 175℃,当时可能采用相似的烧成技术。

We conducted analyses of six shards of export blue and white porcelain from the Nan’ao Ⅰ shipwreck. The results of elemental analysis show that two shards were produced at Jingdezhen Kiln and the other four produced at Zhangzhou Kiln. The materials for making the body and glaze of these two kilns are different, but both kilns used the same domestic cobalt for the blue pigment. The results of microstructure analysis show that the manufacturing technology for the blue and white porcelain produced at Zhangzhou Kiln is different from that of Jingdezhen Kiln. Blue pigment of Jingdezhen Kiln concentrates at the junction of glaze and body, while that of Zhangzhou Kiln diffuses in the glaze or in the middle of glaze. Image optical coherence tomography(OCT) shows that the smooth bright spots of blue pigment of Zhangzhou Kiln were caused by opacified glaze and homogeneously diffused pigments. The blue and white porcelain of Zhangzhou Kiln may represent a unique technology different from that used for underglaze blue of Jingdezhen Kiln for example. In addition, the results of thermodilatometry show that the firing temperatures of blue and white porcelain of Jingdezhen and Zhangzhou Kilns were 1 160 ℃ and 1 175 ℃, respectively, quite close and both lower than normal, which indicates that the kiln technologies of the two places were similar at that time.