Corrosion Stability of Oxide Coatings Formed by Plasma Electrolytic Oxidation of Aluminum: Optimization of Process Time

CORROSION ◽  
10.5006/0859 ◽  
2013 ◽  
Vol 69 (7) ◽  
pp. 693-702 ◽  
Author(s):  
J.B. Bajat ◽  
R. Vasilić ◽  
S. Stojadinović ◽  
V. Mišković-Stanković
2018 ◽  
Vol 72 (1) ◽  
pp. 47-53 ◽  
Author(s):  
Ramesh Babu Nagumothu ◽  
Arunnellaiappan Thangavelu ◽  
Arun Mohan Nair ◽  
Arun Sukumaran ◽  
Tomson Anjilivelil

2019 ◽  
Vol 84 (8) ◽  
pp. 915-923 ◽  
Author(s):  
Stevan Stojadinovic ◽  
Rastko Vasilic

Plasma electrolytic oxidation (PEO) process of Al?Zn?Si alloy in water solution containing 4 g L-1 sodium metasilicate at constant current density of 400 mA cm?2 was investigated. The species present in PEO micro-discharges and their ionization stages were identified using optical emission spectroscopy technique. The obtained PEO spectrum consists of atomic/ionic lines originating from the elements present both in the substrate (Al, Zn) and the electrolyte (Na, O, H). Apart from atomic and ionic lines, AlO band at 484.2 nm was also detected. Plasma electron number density diagnostics was performed from the H? line shape. The electron temperature of 4000?400 K was estimated by measuring the relative line intensities of zinc atomic lines at 481.05 and 636.23 nm. In addition, surface morphology, chemical and phase composition of oxide coatings were investigated by SEM-EDS and XRD. Oxide coating morphology is strongly dependent of PEO time. The elemental components of PEO coatings are Al, Zn, O and Si. The oxide coatings are partly crystallized and mainly composed of gamma phase of Al2O3.


2013 ◽  
Vol 78 (5) ◽  
pp. 713-716 ◽  
Author(s):  
Stevan Stojadinovic

In this lecture results of the investigation of plasma electrolytic oxidation (PEO) process on some metals (aluminum, titanium, tantalum, magnesium, and zirconium) were presented. Whole process involves anodizing metals above the dielectric breakdown voltage where numerous micro-discharges are generated continuously over the coating surface. For the characterization of PEO process optical emission spectroscopy and real-time imaging were used. These investigations enabled the determination of electron temperature, electron number density, spatial density of micro-discharges, the active surface covered by micro-discharges, and dimensional distribution of micro-discharges at various stages of PEO process. Special attention was focused on the results of the study of the morphology, chemical, and phase composition of oxide layers obtained by PEO process on aluminum, tantalum, and titanium in electrolytes containing tungsten. Physicochemical methodes: atomic force microscopy (AFM), scanning electron microscopy (SEM-EDS), x-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS), and Raman spectroscopy served as tools for examining obtained oxide coatings. Also, the application of the obtained oxide coatings, especially the application of TiO2/WO3 coatings in photocatalysis, were discussed.


2019 ◽  
Vol 104 ◽  
pp. 109957 ◽  
Author(s):  
Joanna Michalska ◽  
Maciej Sowa ◽  
Magdalena Piotrowska ◽  
Magdalena Widziołek ◽  
Grzegorz Tylko ◽  
...  

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