湖北省出土的若干青铜器锈蚀产物研究

STUDY ON CORROSION PRODUCTS OF SOME AMCIENT BRONZES EXCAVATED FROM HUBEI PROVINCE

利用X射线衍射结合金相分析对左塚墓地青铜样品进行了研究.结果表明:其锈蚀产物主要为Cu2O、SnO2、PbCO3、PbSO4.4PbO及SiO2;经锻打加工后,青铜器抗腐蚀性能得到提高;表面存在'锡汗'现象的青铜器也比较耐腐蚀;左塚青铜器优先腐蚀α相,;δ相在此类腐蚀环境中比较稳定,抗腐蚀能力较强.拉曼光谱对几件九连墩青铜器锈蚀分析表明,其锈蚀产物有CuCO3.Cu(OH)2(绿铜矿)及2CuCO3.Cu(OH)2(蓝铜矿).同时探讨了以上青铜器的锈蚀机理,并与发掘前青铜器保存状况做了对比分析,揭示出O2、CO2、H2O等是促使青铜器进一步锈蚀的关键因素.在此基础上提出了科学保护此地出土青铜器的简要方法.

XRD was used to identify corrosion products of samples of ancient bronzes from Zuozhong tombs. The result indicates that the main corrosion products were：Cu2O ,SnO2 ,PbCO3 ,PbSO4 · 4PbO and SiO2. From the coross-sectional metallography of ancient bronzes ,we find that the bronze which was forged after founded can hardly be corroded as well as the bronze with tin sweat on its surface. We also find the α phase was corroded preferentially, while the δ phase of the eutectoid still remains uncorroded. Raman spectroscopy was used to identify corrosion products of samples of ancient bronzes from Jiuliandun tombs. The result indicates that Malachite （CuCO3 · Cu（ OH）2 ） is the main substance of green rust and azurite （2CuCO3 · Cu（OH） 2 ） is the main substance of blue rust. Based on the XRD and Raman analysis,it indicates that O2 ,CO2 ,H2O are the main factors for further corrosion of the ancient bronzes. Finally ,we proposed scientific measures for protection of these bronzes.