Effect of phosphate ions on electrochemical behaviour of copper in sulphate solutions


Kilincceker G. , Yazici B. , Yilmaz A., Erbil M.

BRITISH CORROSION JOURNAL, cilt.37, ss.23-30, 2002 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 37 Konu: 1
  • Basım Tarihi: 2002
  • Doi Numarası: 10.1179/000705902225002367
  • Dergi Adı: BRITISH CORROSION JOURNAL
  • Sayfa Sayıları: ss.23-30

Özet

The effect of phosphate ions oil the corrosion behaviour of copper ill sulphate solutions was investigated at different temperatures (293, 313, 333, and 353 K) and at different pH rallies (pH = 2.1, 7.2, and 12.3). A three elcctrode electrochemical technique was used for the measurements, using a saturated calomel electrode (SCE) for reference purposes. Both anodic and cathodic polarisation curves were established, from which the anodic and cathodic Tafel constants were determined. Corrosion potentials were determined by extrapolation of the anodic and cathodic Tafel lines to the point of zero current density. The results showed that for a pH value of 2.1, the corrosion rate of copper showed a Marked tendency to increase with increasing temperature ill solutions containing either sulphate alone or sulphate plus phosphate. However, at pH values of 7.2 and 12.3, this tendency became less pronounced in solutions containing sulphate alone and in solutions containing sulphate pills phosphate together, maximum corrosion rates were greatly reduced and showed less tendency to increase with increasing temperature. Anodic and cathodic reaction mechanisms are proposed to explain the observations for the corrosion of copper.