青铜文物表面腐蚀产物的组成及深度分布研究

CORROSION PRODUCTION ON ARCHAEOLOGICAL BRONZE SURFACE AND ITS DISTRIBUTION WITH DEPTH

青铜在模拟环境介质中的循环伏安实验及XRD测试结果表明,氧化过程主要为生成有害锈CuCl的过程,还原过程主要为CuCl还原成纯铜晶粒的过程,并且反应电流较大,对青铜基体的破坏性较大.运用高性能二次离子质谱(SIMS)观测到不同腐蚀电位下青铜表面腐蚀产物中均含有Cu、Sn、Cl、O、C、S元素,阴离子相对含量由大到小为Cl、O、C、S;腐蚀产物层由表及里Cu/Sn值始终小于合金中Cu/Sn,并且Cu离子含量基本不变,Sn离子含量有起伏,Cl、O离子含量有所下降.

The results of cycle voltammetry(CV) experimentation in simulated environment medium and XRD test are that main oxidation process is harmful patina CuCl formation and reduction process is CuCl reduced or deoxidised to pure Cu.The reaction current is so high that severely damages to bronze substrate.When bronze was corroded respectively at several potentials there exist elements Cu,Sn,Cl,O,C,S in corrosion production on bronze surface with SIMS observation.From high to low the relative content of anions is Cl,O,C,S.Cu/Sn value from outside and in corrosion production is always less than that in alloy.The relative content of Cu is basically stead,Sn fluctuates,Cl or O a little falls.