Corrosion Mechanisms of Copper Investigated by Channel Flow Electrode Method and Electrochemical Impedance Spectroscopy

• Project/Area Number: 15560630
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Material processing/treatments
• Research Institution: Tokyo University of Science
• Principal Investigator: ITAGAKI Masayuki Tokyo University of Science, Faculty of Science and Technology, Professor, 理工学部, 教授 (90266908)
• Project Period (FY): 2003 – 2004
• Project Status: Completed (Fiscal Year 2004)
• Budget Amount: ¥2,200,000 (Direct Cost: ¥2,200,000); Fiscal Year 2004: ¥700,000 (Direct Cost: ¥700,000); Fiscal Year 2003: ¥1,500,000 (Direct Cost: ¥1,500,000)
• Keywords: copper / corrosion / channel flow electrode / electrochemical impedance / 塩化物イオン / 硫酸イオン / チャンネルフロー電極法 / アノード溶解反応機構

Research Abstract

Anodic dissolution mechanisms of copper in many kinds of electrolyte solutions were investigated by a channel flow electrode method and an electrochemical impedance spectroscopy. The detections of cuprous and cupric ions, which are dissolved from copper working electrode, are carried out simultaneously with the measurements of polarization curves. On the basis of reaction parameters obtained by the above-mentioned experiments, the detail dissolution mechanisms of copper were discussed.
The roles of ions presenting in the electrolyte solutions were classified into as follows.
The species accelerating the dissolution rate : Cl^-,SO_4^<2->,H_2PO_4^-,SO_2^-,NO_3^-,NO_2^-,ClO^-.
The species inhibiting the dissolution rate : HPO_4^<2->.
The species whose role depends on the environment : HCO_3^-,CO_3^<2->,NH_4^+.