【作者】 许淳淳； 吕国诚； 王菊琳；

【Author】 Xu Chunchun Lv Guocheng Wang Julin (Beijing University of Chemical Technology)

【机构】 北京化工大学；

【摘要】 用模拟闭塞电池法(O.C.)对青铜在模拟环境介质0.028 mol·L-1 NaCl+0.01mol·L-1 Na2SO4+0.016 mol·L～1 NaHCO3中局部腐蚀孔内或裂纹内的化学变化进行了研究,通电32h后闭塞区内溶液的pH值由7.00降至5.03,与此同时Cl-和SO42-向闭塞区内迁移,其浓集倍数分别是6.31和2.93:测定了闭塞区内外铜、锡、铅金属离子的浓度,据此计算出溶解因子fSn/Cu小于1,fPh/Cu大于1,表明青铜中各元素选择性腐蚀的顺序为铅>铜>锡,腐蚀速度为铅>铜>锡;用XRD分析了腐蚀产物的组成,解释了青铜文物表面腐蚀产物的分层现象,即从里到外为CuCl,CuCl和Cu2O,铜的二价化合物。用循环伏安法(CV)研究了青铜/模拟闭塞溶液界面上的电化学行为,从不同通电时间闭塞区溶液氧化还原反应出峰电位及阴极和阳极电流峰值的大小,研究了腐蚀产物生成过程和速度,探明了腐蚀产物CuCl(产生青铜病的有害锈)的生成机理及促进腐蚀的特点。对循环伏安谱中各个氧化还原峰电位下生成的产物组成用XRD进行了检测。更多还原

【Abstract】 A simulated occluded cell (O. C.) was used on the study of chemical changes in the local corrosion pits or crevices of archaeological bronze in simulated environment medium (0. 028 mol · L-1 NaCl+0. 01 mol - L-1 Na2SO4+0. 016 mol · L-1 NaHCO3). It is found that as anodic current passing the cell for 32hours, the pH value decreases from 7.00 to 5.02, meanwhile Cl- and SO42- migrate into the O. C. and their concentrate rate can reachs 6.31 and 2.93 respectively. The metallic ion concentrations of Cu, Sn, and Pb in the O. C. and bulk solution were measured. Then, the concentrations were used to calculate dissolution factors, f Sn/cu and f Pb /Cu. The results of f Sn/Cu < 1 and f Pb/Cu > 1 indicate that the selective dissolution order and corrosion rates are Pb>Cu>Sn. XRD was used on analyzing the composition of corrosion products and explaining how the products to be layered on bronze surface. Cycle voltammetry (CV) technique is utilized on the study of electrochemistry behavior of bronze /simulated occluded solution interface. The potential and current peaks ofoxidation-reduction at the cathode and anode in occluded solution at various time intervals induce a study of corrosion products formation process and their formation speed. The mechanism of CuCl(harmful patina which generate "bronze disease" ) production and corrosion accelerate is also characterized. XRD is applied to analyze production occurred at oxidation or reduction potentials.更多还原