9 research outputs found
<i style="">Salvia officinalis</i> L. honey as corrosion inhibitor for CuNiFe alloy in sodium chloride solution
96-102Salvia officinalis L. honey has been tested as
inhibitor for the corrosion of CuNiFe alloy in 0.5 M NaCl solution by
electrochemical measurements. The honey solutions are prepared in different
concentrations, such as 400, 600, 800, 1000 and 1200 ppm. Polarization curves
show that the honey acts as mixed corrosion inhibitor, and the inhibition
efficiency increases with an increase in honey concentration. The maximum
corrosion inhibition efficiency of approximately 70 % is achieved with the
highest inhibitor concentration (1200 ppm of honey). Changes in impedance
parameters are indicative of adsorption of honey compounds on the metal
surface. The adsorption of natural honey on the CuNiFe alloy follows the
Langmuir adsorption isotherm
Corrosion inhibition of Al-Mg alloy by gentisic acid
89-94Gentisic acid
was studied for possible use as an Al-2.5Mg alloy corrosion inhibitor in a 0.5
mol dm-3 NaCl solution. Investigations were performed on a rotating
disc electrode in a quiescent solution at different electrode rotation rates
and electrolyte temperatures. The results indicate that, the addition of
gentisic acid inhibits corrosion of Al-2.5Mg alloy, and the inhibition
efficiency increases with increasing inhibitor concentration but decreases with
increasing electrode rotation rate and electrolyte temperature. The
investigated compound acts as a cathodic-type inhibitor and the inhibition is
ascribed to the adsorption of the inhibitor onto the electrode surface. The
adsorptive behaviour of gentisic acid follows the Freundlich adsorption
isotherm
Effect of Nb alloying additions on the characteristics of anodic oxide films on zirconium and their stability in NaOH solution
The characteristics of oxide films on Zr and Zr- Nb alloys (with Nb content of 2.5, 5, and 10 at.%) galvanostatically formed (at a current density of 100 μA cm−2) in 0.5 M H2SO4 solution were investigated by means of electrochemical impedance spectroscopy. Electrochemical impedance spectroscopy spectra were interpreted in terms of an "equivalent circuit" with the circuit elements representing the electrochemical properties of a single layer oxide. The resistance of the oxide films was found to increase with increased Nb content in the alloy while the capacitance showed an opposite trend. The stability of the anodic oxide films grown in the sulfuric acid solution on Zr and Zr-Nb alloys was investigated by simultaneously measuring the electrode capacitance and resistance at a working frequency of 1 kHz as a function of exposure time to naturally aerated 3 M NaOH solution. Analyses of the electrode capacitance and resistance values indicated a decrease in chemical dissolution rate of the oxide films with the increase of Nb content in the alloy
Repairing the specified track on the copper coating surface via area-selective electrodeposition
Effect of Annealing on Microstructure and Tensile Properties of 5052/AZ31/5052 Clad Sheets
Influence of Zn and Mg Alloying on the Corrosion Resistance Properties of Al Coating Applied by Arc Thermal Spray Process in Simulated Weather Solution
In this study, Al–Zn and Al–Mg coatings were deposited on steel substrates by an arc thermal spray process. X-ray diffraction and scanning electr on microscopy were used to characterize the deposited coatings and corrosion products. Open circuit potential (OCP), electrochemical impedance spectroscopy, and potentiodynamic studies were used to assess the corrosion characteristics of these coatings after exposure according to the Society of Automotive Engineers (SAE) J2334 solution of varying durations. This solution simulates an industrial environment and contains chloride and carbonate ions that induce corrosion of the deposited coatings. However, the Al–Mg alloy coating maintained an OCP of approximately - 0.911 V versus Ag/AgCl in the SAE J2334 solution even after 792 h of exposure. This indicates that it protects the steel sacrificially, whereas the Al–Zn coating provides only barrier-type protection through the deposition of corrosion products. The Al–Mg coating acts as a self-healing coating and provides protection by forming Mg 6 Al 2 (OH) 16 CO 3 (Al–Mg layered double hydroxides). Mg 6 Al 2 (OH) 16 CO 3 has interlocking characteristics with a morphology of plate-like nanostructures and an ion-exchange ability that can improve the corrosion resistance properties of the coating. The presence of Zn in the corrosion products of the Al–Zn coating allows dissolution, but, at the same time, Zn 5 (OH) 6 (CO 3 ) 2 and Zn 6 Al 2 (OH) 16 CO 3 are formed and act to reduce the corrosion rate