ECAP制备超细晶铜在0.5mol/L NaCl溶液中的腐蚀行为

摘要

利用极化法、电位时间曲线、浸泡实验等研究等径角挤压(Equal Channel Angular Pressing,ECAP)制备的块体超细晶铜和退火态粗晶铜在0.5mol/L NaCl溶液中的腐蚀行为,对比研究ECAP挤压前后腐蚀行为的变化.结果表明:通过ECAP制备的超细晶Cu的腐蚀电流低于粗晶Cu,自腐蚀电位Ecorr比粗晶铜高100mV左右,表明超细晶Cu的耐蚀性比粗晶Cu要好.通过电化学分析和微观腐蚀形貌,超细晶材料的腐蚀表面非常光滑,腐蚀较为均匀,粗晶材料的局部腐蚀现象十分严重.%The corrosion behavior of ultra-fine grain (UFG) copper bulk prepared by equal channel angular pressing (ECAP) was investigated in comparison with that in recrystallized coarse grain (CG) copper in 0.5mol/L NaCl solution by Tafel extrapolation method,E-t curve and immersion corrosion tests.Corrosion current was estimated by Tafel extrapolation method to examine the kinetics of corrosion in 0.5mol/L NaCl solution.The result shows that UFG copper exhibits a lower corrosion current and high self-corrosion potential in comparison with CG copper.UFG copper has higher corrosion resistance compared with CG copper.Corrosion damage on the surface of UFG copper is macroscopically rather smooth and uniform whereas localized corrosion of CG copper is very severe for obvious attacking at grain boundaries and selective corrosion of some grain by using electrochemical analysis and microscopic corrosion morphology.