F. H. Assaf

Stripping voltammetric and conductance measurements on corrosion and inhibition of copper in nitric acid

The kinetics of copper dissolution in nitric acid especially, the phase of dissolution at the beginning of incubation period was investigated. Two techniques, the anodic stripping voltammetry and the conductance measurements, were used for the first time in this concern. Galvanostatic polarization measurements using very simple circuit used to study the corrosion process of copper in nitric acid. The effect of several factors was studied, namely nitric acid concentration, the copper surface area and stirring. The effect of inorganic substances and their role as inhibitors or promoters was also investigated. By applying the anodic stripping voltammetric technique it was found that the rate of copper dissolution during the incubation period is constant and time independent. Also, stirring prevents the corrosion of copper almost completely.

Corrosion resistance and electrodeposition behavior of electrodeposited nickel‐cobalt‐iron alloys

Purpose – The purpose of this paper is to investigate the corrosion resistance and the electrodeposition behavior of electrodeposited nickel‐cobalt‐iron alloys. Also, to compare the electrodeposition of ternary nickel‐cobalt‐iron alloy from acidic sulfate bath onto a steel substrate with the characteristics of Co‐Fe electrodeposits.Design/methodology/approach – The investigation of electrodeposition was carried out using cyclic voltammetry and galvanostatic techniques, while potentiodynamic polarization resistance and anodic linear sweep voltammetry techniques were used for corrosion study. The phase structure was characterized by means of X‐ray diffraction analysis. The surface morphology and chemical composition of the deposits were examined by using scanning electron microscopy and atomic absorption spectroscopy, respectively.Findings – The obtained results revealed that the Ni‐Co‐Fe alloys consisted of a mixture of iron (Fe10.8Ni) and (FeCo) phases. It was found that the obtained Ni‐Co‐Fe alloy exhibi...

Studies on dissolution and inhibition of copper in nitric acid using stripping voltammetry and conductance measurement

Abstract Stripping voltammetry and conductance measurements were used for the first time to study the corrosion and inhibition of copper. The effect of nitric acid concentration, temperature and some organic compounds on the corrosion rate was studied. Regression analysis using four modes (linear, logarithmic, power and exponential) was used to correlate the results. Data obtained showed that the linear regression is the best to fit the relationship between Cu2+ concentration–time (stripping voltammetry) and conductance–time (conductance measurements). The inhibition efficiencies of the organic substances during the active stage of copper dissolution are generally lower than in the incubation period. The increase in temperature and nitric acid concentration brought about a parallel increase in the corrosion rate. Galvanostatic polarization measurements, using simple circuit, were used to study the corrosion process of copper in nitric acid.