ELECTROCHEMICAL FEATURES DURING PITTING CORROSION OF LY12 ALUMINUM ALLOY IN DIFFERENT NEUTRAL SOLUTIONS  

作　　者：Y.L.Cheng J.F.Li J.Q.Zhang C.N.Cao F.H.Cao Z.Zhanq 

机构地区：[1]DepartmentofChemistry,YuquanCampus,ZhejiangUniversity,Hangzhou310027.China [2]StateKeyLaboratoryforCorrosionandProtectionofMetals,InstituteofMetalResearch.TheChineseAcademyofSciences,Shenyang110016,ChinaManuscriptreceived10July2002 inrevisedform10October2002

出　　处：《Acta Metallurgica Sinica(English Letters)》2003年第4期319-326,共8页金属学报（英文版）

基　　金：The authors wish to acknowledge the financial supports of the National Key Basic Research Foundation of China(Grant No.G1999065001);the National Natural Science Foundation of China(Grant No.50071054);the State Key Laboratory for Corrosion and Protection of Metals(China).

摘　　要：The electrochemical features of commercial airfrarne material, Al alloy LY12, in 0.349mol/L neutral sodium chloride (NaCl) and sodium sulfate (NazSO^) solutions were investigated by electrochemical impedance spectroscopy (EIS) and potentiody-namic polarization techniques. The microstructure of the as-tested samples was studied by scanning electron microscopy. The results show that the Nyquist plots of LY12 at different immersion time displayed different features, indicating that the Cl- ions elevate the corrosion rate and inhibit the repassivation of a metastable pit. It also shows that the corrosion product of LY12 formed in SO42- solution isn't easy to dissolve, and it will cover the surface of working electrode in the electrolyte. SEM images indicate that the corrosion apparent area and pit number of LY12 in NaCl solution are greater than that in Na2SO4 solution.The electrochemical features of commercial airfrarne material, Al alloy LY12, in 0.349mol/L neutral sodium chloride (NaCl) and sodium sulfate (NazSO^) solutions were investigated by electrochemical impedance spectroscopy (EIS) and potentiody-namic polarization techniques. The microstructure of the as-tested samples was studied by scanning electron microscopy. The results show that the Nyquist plots of LY12 at different immersion time displayed different features, indicating that the Cl- ions elevate the corrosion rate and inhibit the repassivation of a metastable pit. It also shows that the corrosion product of LY12 formed in SO42- solution isn't easy to dissolve, and it will cover the surface of working electrode in the electrolyte. SEM images indicate that the corrosion apparent area and pit number of LY12 in NaCl solution are greater than that in Na2SO4 solution.

关 键 词：LY12 aluminum alloy pitting corrosion electrochemical impedance spectroscopy potentiodynamic polarization pit- morphology 

分 类 号：TG174.36[金属学及工艺—金属表面处理]