Acta Phys. -Chim. Sin. ›› 2006, Vol. 22 ›› Issue (03): 312-315.doi: 10.3866/PKU.WHXB20060311

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The Cooperative Inhibition Effects of Alkaline Earth Metal Ions and EDTA on the Corrosion of Pure Aluminum in an Alkaline Solution

SHAO Hai-Bo; WANG Xiao-Yan; WANG Jian-Ming; WANG Jun-Bo; ZHANG Jian-Qing; CAO Chu-Nan   

  1. Department of Chemistry, Zhejiang University, Hangzhou 310027, P. R. China; State Key Laboratory for Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110015, P. R. China
  • Received:2005-09-01 Revised:2005-10-24 Published:2006-03-10
  • Contact: SHAO Hai-Bo E-mail:dhx318@zjuem.zju.edu.cn

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Abstract: The cooperative effects of alkaline earth metal ions and EDTA(ethylenediamine tetraacetic acid) on the corrosion inhibition of pure aluminum in 4 mol•L-1 KOH solution were investigated by hydrogen collection, polarization curve and electrochemical impedance spectroscopy(EIS). It was found that aluminum exhibits minimum corrosion rate in 4 mol•L-1 KOH solution containing 0.02 mol•L-1 EDTA, saturated Ca(OH)2 and saturated Sr(OH)2. EDAX analysis showed that alkaline earth metal ions and EDTA have no contribution to the formation of the surface film on aluminum. Therefore the inhibition effect may be caused by the adsorption of the inhibitor on aluminum surface. This fact indicates that these two ions act as interface inhibitors rather than inter-phase ones.

Key words: Pure aluminum, Alkaline solution, Corrosion, Alkaline earth metal, EDTA, Inhibitor