我国古代建筑绿色琉璃构件病害的分析研究

Research on Diseases & Damages to Green-Glazed Tiles on Chinese Traditional Architecture

在对我国不同地区古代建筑绿色琉璃构件的调研中,发现主要病害是釉面存在白色或土灰色腐蚀物。为弄清这一病害的成因及危害,本文挑选46个我国不同地区古代建筑绿色琉璃构件样品,利用光学显微镜(OM)、X射线衍射(XRD)、X射线荧光(XRF)、扫描电镜-能谱(SEM-EDS)等方法,对琉璃构件表面腐蚀物的成分和结构进行了分析与观察。结果表明:建筑绿色琉璃构件表面腐蚀物为磷氯铅矿和硫酸铅的混合物,腐蚀物自表层釉逐层向里层釉形成,其结构并不致密,呈蜂窝状。光电子能谱(XPS)结果表明,铅在釉中以网络调节剂的形式存在,容易溶出,绿色琉璃釉中着色元素铜的存在会使铅的溶出量大大增加;溶出的铅离子会和大气粉尘中含磷、硫、氯元素的阴性离子化合物发生化学反应,沉积在绿色琉璃构件釉面形成腐蚀物。

This paper makes an analysis of the white and dusty gray substances causing the diseases and damages to the green-glazed tiles from 46 selected Chinese historical architectures nationwide by means of optical microscope (OM), X-ray diffraction (XRD), X-ray fluorescence (XRF) and scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS), summing up the following results: The corrosive substances on the surface of the tiles are the mixture of pyromorphite and lead sulfate with loose and alveolate structure, which develop downward the layers of glaze; A lot of lead working as network modifier tends to leach under the effect of copper which serves as a green colorant for glaze. In addition, the lead ions leaching out of the glaze react with anionic components like phosphorus, sulfur and chlorine from atmosphere dust to form the corrosive substances left over on the glaze.