Comparative study of electrochemical Corrosion of Novel Designs of 90/10 and 70/30 Copper-Nickel Alloys in Brine Solutions | ||
| Egyptian Journal of Chemistry | ||
| Article 26, Volume 63, Issue 4, April 2020, Pages 1527-1540 PDF (1.87 M) | ||
| Document Type: Original Article | ||
| DOI: 10.21608/ejchem.2019.16389.2001 | ||
| Authors | ||
| Ghalia Asaad Gaber* 1; Walaa A. Hussein2; Amal S. I. Ahmed2 | ||
| 1Faculty of science, chemistry department, Al Azhar University | ||
| 2Chemistry Department, Faculty of Science (Girls), Al-Azhar University, Nasr City, Cairo, Egypt. | ||
| Abstract | ||
| Copper-nickel alloy is a material of choice for condensers and heat exchangers, where seawater is used as a coolant and in desalination plants. In this work, we survey the comparative corroding behavior of novel designs of 90/10 and 70/30 Copper-Nickel alloys under higher salinity (3.5 wt%, 10 wt% and 15 wt% NaCl). The electrochemical corrosion of Cu-Ni alloys in brine solutions was studied using potentiodynamic polarization, chronoamperometric and electrochemical impedance spectroscopy measurements along with scanning electron microscope (SEM) and energy dispersive X-Ray analyzer (EDX) investigations. Polarization data showed that Cu-10 Ni alloy is more corrosive than Cu-30 Ni alloy in 3.5 wt% NaCl solutions. Chronoamperometric curves confirmed the results obtained by polarization measurements that the uniform and pitting corrosion of Cu-Ni alloy were reduced in the Cu-30 Ni alloy in 3.5wt% NaCl solutions. Impedance spectra revealed that the surface and polarization resistances recorded higher values in Cu-30Ni alloy. SEM/EDX investigations indicated that the corrosion of Cu-Ni alloys proceeded by the selective electro-dissolution of nickel, which allowed copper enrichment on the surface of the alloy. The heat exchanger served to heat desalinated water, the water had a high chloride level. Corrosion examination indicated susceptibility towards pitting corrosion, especially at high temperature. | ||
| Keywords | ||
| Corrosion; Cu-Ni Alloys; Brine Solutions; Electrochemical Techniques; Spectroscopic Analysis | ||
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