The Electrochemical Behaviour of 70-30 Cu-Ni Alloy in LiBr Solutions | ||
| Egyptian Journal of Chemistry | ||
| Article 11, Volume 59, Issue 5, October 2016, Pages 833-850 PDF (932.01 K) | ||
| DOI: 10.21608/ejchem.2016.1471 | ||
| Abstract | ||
| THE BEHAVIOUR of 70-30Cu-Ni alloy has been investigated in different concentrations of LiBr solutions from 10-1 to 9 M. Electrochemical measurements and surface examination complemented with solution analysis were carried out. The results revealed that the passivation current of (Ip1) at low anodic potential (-200) is due to the formation of a doped Cu2O film involving surface enrichment of nickel. Increasing the anodic potential to ≥ 300 mV, after the formation of a peak of anodic current maximum (Ip2) a partially passive film of Cu2(OH)3 Br is formed and the surface suffered from denicklefication. Furthermore, solution analysis proves that the alloy dissolves showing a copper/ nickel ratio in solution which approximation complete that of the alloy surface . Two types of pitting corrosion were recorded at 2 and 4 M LiBr, the first one was recorded after Ip1 while the second is recorded after +1000mV. Except the concentration of 2 and 4 M the first one only of pitting which recorded after Ip1 were observed beside the general dissolution through the partially soluble Cu2(OH)3Br. | ||
| Keywords | ||
| Copper -Nickel; LiBr; Denicklefication; Pitting corrosion and general dissolution | ||
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