Cerium Compounds Coating as a Single Self-Healing Layer for Corrosion Inhibition on Aluminum 3003

Abstract

The formation of cerium hydroxide was studied, and its capacity as a corrosion inhibitor on aluminum substrates was evaluated. These particles were deposited by immersing the substrate in a bath with cerium nitrate and hydrogen peroxide. Four different immersion times were used to determine the differences in behavior from low concentrations to an excess of particles on the surface. The coatings were analyzed morphologically by scanning electron microscope (SEM) and optical microscope, and chemically by energy dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). Electrochemical corrosion analysis was studied using cyclic potentiodynamic polarization (CPP), electrochemical impedance spectroscopy (EIS), and electrochemical noise (EN). The results show that for 2 and 5 min of immersion, there was corrosion inhibition caused by the presence of cerium Ce3+ in the coating, but with excess cerium hydroxide particles, corrosion was favored. The presence of cerium particles favors corrosion at 30 s of immersion. This is the same case at 60 min, where corrosion was favored by the excess of Ce4+ particles on the surface.

Unraveling the role of internal–external metal substitution in Zn3[Co(CN6)]2 for the styrene oxide–CO2 cycloaddition reaction

“…For the charge reference, the adventitious carbon was set at 284.8 eV; the chosen value was the most consistent in the literature. 47–57 Fig. 2 shows high-resolution spectra of the most important elements.…”

“…50 The area values were lower than the main cyanide group values. The peak at 285.7 eV corresponds to sp 2 hybridization in the carbon–nitrogen bond, 48 and the peak at 287 eV is assigned to C–O bonding 48–57 and is probably due to oxidation at the edges of the particles; the contribution area is very low (about 2%). The nitrogen core level is shown in Fig.…”

Probing Localised Corrosion Inhibition of AA2024-T3 by Integrating Electrode Array, SVET, SECM, and SEM-EDS Techniques

“…In order to inhibit localised corrosion, corrosion inhibitors should have the capacity to interact over various lengths and time scales to match those time-dependent processes occurring on alloy surfaces. Environmentally friendly rare earth (RE) compounds have demonstrated complex multiscale interactions when inhibiting corrosion reactions on aluminium alloys, for instance, AA2024-T3 [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20].…”

“…Extensive studies have been carried out over previous years on the corrosion inhibition of AA2024-T3 by RE inhibitors [8][9][10][11][12][13][14][15][16][17][18][19][20] using a range of electrochemical techniques including standard electrochemical techniques, volta potential methods (e.g., scanning Kelvin probe (SKP)), scanning vibrating electrode technique (SVET), scanning electrochemical microscopy (SECM) and electrochemically integrated multi-electrode arrays (also known as wire beam electrode (WBE)) under different environmental conditions. Many of the past studies have examined corrosion in the presence of the inhibitors under electrochemical polarisation conditions, not under open circuit potential (OCP) corrosion conditions.…”

“…An AA2024-T3 wire was selected due to its high-strength, complex microstructure and its importance in the aerospace industry. The inhibitor cerium diphenyl phosphate, Ce(dpp) 3 , is studied in this research as an example of an environmentally friendly inhibitor that is known to be an efficient corrosion inhibitor for Al alloys, especially Al-Cu-Mg alloys (e.g., AA2024-T3) [10][11][12][16][17][18]20,28].…”