青铜文物光电子能谱分析

X-ray Photoelectron Spectroscopy Studies of Archeological Bronzes

采用光电子能谱(XPS)分析方法研究了成都金沙遗址出土铜条和方孔型器两种青铜表面锈层膜的元素及其化学状态。实验结果表明,铜条和方孔型器青铜的锈层膜中都存在纯铜晶粒和PbCO3/PbO,但没有发现导致“青铜病”的有害Cl元素,而在方孔型器锈层膜中发现有S2-/SO42-。铜条和方孔型器夹层锈层膜中的Sn元素完全以SnO2形式存在,从而使青铜合金免遭进一步腐蚀。此外,还结合实验结果讨论了青铜的腐蚀过程与环境之间的关系。

The main purpose of this work is to study the corrosion mechanism of the bronze wares excavated from Jinsha site near Chengdu by means of X-ray photoelectron spectroscopy(XPS).The results showed that the corrosion products on the surface of the archeological bronzes are rich in free copper grains and lead carbonates/oxides.However,chlorine,which may lead to the formation of corrosion patinas on bronze surfaces under air atmosphere,has not been detected.XPS measurements also showed that S was in the form of S^(2-)/SO_4^(2-) on the surface of the square-hole bronze.Tin,entirely present as a SnO_2-like phase,in the corrosion products of copper strip and the interface between outer layer and the base of the square-hole bronze,preventing further corrosion of the archeological bronzes.The relationship between corrosion mechanism of the archeological bronze and the underground environment has also been discussed.