Papers by Keyword: Tafel Curve

Abstract: The ceria coatings on AZ91 substrates were successfully synthesized by chemical conversion and the corrosion resistance of AZ91 samples with and without ceria coatings were evaluated by means of electrochemical corrosion in 3.5 wt.% NaCl solution. According to the parameters derived from the polarization date, the I_corr (the corrosion current density) values of the coated samples are smaller than that of bare one, indicating that the corrosion resistance of AZ91 alloys has been improved to some extent. The influence of fluoridated pretreatment, inter-layer heat treatment, sintering temperature and the layer of films on the performance of ceria coatings were also investigated. It was found that the inter-layer heat treatment has no influence on improving the anticorrosion resistance of AZ91 alloy. In comparison with the bare one, the I_corr of optimal sample is about 0.0219mA/cm², which decreases by two orders of magnitude, indicating that the ceria coatings could significantly improve the corrosion resistance of AZ91 magnesium alloy.

Abstract: Polymerization of p-chloroaniline (CA) was achieved electrochemically in aqueous solution containing H2SO4 as supporting electrolyte. The films were obtained by applying sequential linear potential scan rate 20mV/s between -0.5 to 1.5V versus Ag/AgCl electrode. The polymer was characterized by UV-visible and FT-IR spectroscopy. We observed the morphologies of PCA films through the scanning electronic microscope (SEM), showing island protruding structure. The Tafel curves showed that PCA can be used as anti-corrosion material.

Abstract: Alloy 600 was studied in different Na2SO4 solutions with three approaches including Tafel curve method, AC impedance curve and high temperature experiment. Experimental results showed that interface electric transfer process was the control step of whole electrochemistry process; and selective corrosion of Alloy 600 would not happen in high temperature process

Abstract: Abstract: Alloy 600 was studied in different acidic environments with three approaches including Tafel curve method, linear polarization method and AC impedance curve. Experimental results showed that there was greatest corrosion velocity when pH was 4 for preventing film factor; and it was possibly caused by elements corrosion dissolving with different proportional compared with Alloy 600 metallurgical contents.

Abstract: Microstructure and bio-corrosion properties of as-cast Mg-Zn-Mn-Y alloys are investigated in detail to reveal the effect of the precipitate on the biocorrosion properties for biomedical application by scanning electronic microscopy electrochemical measurement and immersion tests. Alloy I is composed of primary Mg, Mg7Zn3 and I-phase, while there is only one secondary phase (W-phase) in alloy II. Alloy with W-phase exhibits a higher corrosion resistance and a lower corrosion current density. W-phase acts as a cathode and Mg matrix as an anode at the interface between W-phase and Mg matrix, while I-phase acts as an anode and Mg matrix as a cathode. The standard electrode potentials of secondsry phases are in the following order: W-phase>Mg>I-phase.