scholarly journals Optimization of Surface Properties of Plasma Electrolytic Oxidation Coating by Organic Additives: A Review

Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 374
Author(s):  
Mosab Kaseem ◽  
Burak Dikici
Keyword(s):  
Plasma Electrolytic Oxidation ◽  
Electrical Response ◽  
Industrial Applications ◽  
Plasma Discharges ◽  
Organic Additives ◽  
Plasma Electrolytic Oxidation Coating ◽  
Electrolytic Oxidation ◽  
Plasma Electrolytic ◽  
Organic Amines ◽  
Peo Coatings

Plasma electrolytic oxidation (PEO) is an effective surface modification method for producing ceramic oxide layers on metals and their alloys. Although inorganic electrolytes are widely used in PEO, the organic additives have received considerable interest in the last decade due to their roles in improving the final voltage and controlling spark discharging, which lead to significant improvements in the performance of the obtained coatings. Therefore, this review summarized recent progress in the impacts of organic additives on the electrical response and the plasma discharges behavior during the PEO process. The detailed influence of organic additives, namely alcohols, organic acids, organic amines, organic acid salts, carbohydrate compounds, and surfactants on the corrosion behavior of PEO coatings is outlined. Finally, the future aspects and challenges that limit the industrial applications of PEO coating made in organic electrolytes are also highlighted.

scholarly journals Plasma Electrolytic Oxidation (PEO) Process—Processing, Properties, and Applications

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1375
Author(s):  
Soumya Sikdar ◽  
Pramod V. Menezes ◽  
Raven Maccione ◽  
Timo Jacob ◽  
Pradeep L. Menezes
Keyword(s):  
Plasma Electrolytic Oxidation ◽  
Nanocomposite Coatings ◽  
Mechanical And Tribological Properties ◽  
Electrolytic Oxidation ◽  
Recent Developments ◽  
Coating Formation ◽  
Wear And Corrosion Resistance ◽  
Plasma Electrolytic ◽  
Peo Coatings ◽  
Future Work

Plasma electrolytic oxidation (PEO) is a novel surface treatment process to produce thick, dense metal oxide coatings, especially on light metals, primarily to improve their wear and corrosion resistance. The coating manufactured from the PEO process is relatively superior to normal anodic oxidation. It is widely employed in the fields of mechanical, petrochemical, and biomedical industries, to name a few. Several investigations have been carried out to study the coating performance developed through the PEO process in the past. This review attempts to summarize and explain some of the fundamental aspects of the PEO process, mechanism of coating formation, the processing conditions that impact the process, the main characteristics of the process, the microstructures evolved in the coating, the mechanical and tribological properties of the coating, and the influence of environmental conditions on the coating process. Recently, the PEO process has also been employed to produce nanocomposite coatings by incorporating nanoparticles in the electrolyte. This review also narrates some of the recent developments in the field of nanocomposite coatings with examples and their applications. Additionally, some of the applications of the PEO coatings have been demonstrated. Moreover, the significance of the PEO process, its current trends, and its scope of future work are highlighted.

scholarly journals Comparison of Biocompatible Coatings Produced by Plasma Electrolytic Oxidation on cp-Ti and Ti-Zr-Nb Superelastic Alloy

Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 401
Author(s):  
Ruzil Farrakhov ◽  
Olga Melnichuk ◽  
Evgeny Parfenov ◽  
Veta Mukaeva ◽  
Arseniy Raab ◽  
...  
Keyword(s):  
Plasma Electrolytic Oxidation ◽  
Electrochemical Impedance ◽  
Pure Titanium ◽  
Commercially Pure Titanium ◽  
X Ray ◽  
Kinetic Coefficients ◽  
Electrolytic Oxidation ◽  
Plasma Electrolytic ◽  
Cp Ti ◽  
Peo Coatings

The paper compares the coatings produced by plasma electrolytic oxidation (PEO) on commercially pure titanium and a novel superelastic alloy Ti-18Zr-15Nb (at. %) for implant applications. The PEO coatings were produced on both alloys in the identical pulsed bipolar regime. The properties of the coatings were examined using scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy-dispersive X-ray spectroscopy (EDX), potentiodynamic polarization (PDP), and electrochemical impedance spectroscopy (EIS). The PEO process kinetics was modeled based on the Avrami theorem and Cottrell equation using a relaxation method. The resultant coatings contain TiO2, for both alloys, and NbO2, Nb2O5, ZrO2 for Ti-18Zr-15Nb alloy. The coating on the Ti-18Zr-15Nb alloy has a higher thickness, porosity, and roughness compared to that on cp-Ti. The values of the kinetic coefficients of the PEO process—higher diffusion coefficient and lower time constant for the processing of Ti-18Zr-15Nb—explain this effect. According to the electrochemical studies, PEO coatings on Ti-18Zr-15Nb alloy provide better corrosion protection. Higher corrosion resistance, porosity, and roughness contribute to better biocompatibility of the PEO coating on Ti-18Zr-15Nb alloy compared to cp-Ti.

scholarly journals SEM and EDS Characterization of Porous Coatings Obtained On Titaniumby Plasma Electrolytic Oxidation in Electrolyte Containing Concentrated Phosphoric Acid with Zinc Nitrate

2017 ◽  
Vol 17 (2) ◽  
pp. 41-54 ◽  
Author(s):  
K. Rokosz ◽  
T. Hryniewicz ◽  
K. Pietrzak ◽  
W. Malorny
Keyword(s):  
Phosphoric Acid ◽  
Plasma Electrolytic Oxidation ◽  
Pure Titanium ◽  
Zinc Nitrate ◽  
Porous Coatings ◽  
Electrolytic Oxidation ◽  
Micro Arc Oxidation ◽  
Plasma Electrolytic ◽  
Peo Coatings

AbstractThe SEM and EDS results of porous coatings formed on pure titanium by Plasma Electrolytic Oxidation (Micro Arc Oxidation) under DC regime of voltage in the electrolytes containing of 500 g zinc nitrate Zn(NO3)2·6H2O in 1000 mL of concentrated phosphoric acid H3PO4at three voltages, i.e. 450 V, 550 V, 650 V for 3 minutes, are presented. The PEO coatings with pores, which have different shapes and the diameters, consist mainly of phosphorus, titanium and zinc. The maximum of zinc-to-phosphorus (Zn/P) ratio was found for treatment at 650 V and it equals 0.43 (wt%) | 0.20 (at%), while the minimum of that coefficient was recorded for the voltage of 450 V and equaling 0.26 (wt%) | 0.12 (at%). Performed studies have shown a possible way to form the porous coatings enriched with zinc by Plasma Electrolytic Oxidation in electrolyte containing concentrated phosphoric acid H3PO4with zinc nitrate Zn(NO3)2·6H2O.

scholarly journals Effects of a Carbon Nanotube Additive on the Corrosion-Resistance and Heat-Dissipation Properties of Plasma Electrolytic Oxidation on AZ31 Magnesium Alloy

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2438 ◽  
Author(s):  
Myungwon Hwang ◽  
Wonsub Chung
Keyword(s):  
Corrosion Resistance ◽  
Carbon Nanotube ◽  
Plasma Electrolytic Oxidation ◽  
Heat Dissipation ◽  
X Ray ◽  
Steady State Method ◽  
Electrolytic Oxidation ◽  
Plasma Electrolytic ◽  
Dissipation Property ◽  
Peo Coatings

Plasma electrolytic oxidation (PEO) coating was obtained on AZ31 Mg alloy using a direct current in a sodium silicate-based electrolyte with and without a carbon nanotube (CNT) additive. The surface morphology and phase composition of the PEO coatings were investigated through field emission scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The corrosion-resistance properties of the PEO coatings were evaluated using potentiodynamic polarization measurements and electrochemical impedance spectroscopy (EIS) in a 3.5 wt.% NaCl solution. Furthermore, the heat-dissipation property was evaluated by a heat-flux measurement setup using a modified steady-state method and Fourier transform infrared spectroscopy (FT-IR). The results demonstrate that, by increasing the concentration of CNT additive in the electrolyte, the micropores and cracks of the PEO coatings are greatly decreased. In addition, the anticorrosion performance of the PEO coatings that incorporated CNT for the protection of the Mg substrate was improved. Finally, the coating’s heat-dissipation property was improved by the incorporation of CNT with high thermal conductivity and high thermal emissivity.

Plasma Electrolytic Oxidation (PEO) Coatings on Aluminum Alloys: Kinetics and Formation Mechanism

2019 ◽  
Author(s):  
Alex Lugovskoy ◽  
Lyubov Snizhko
Keyword(s):  
Aluminum Alloys ◽  
Plasma Electrolytic Oxidation ◽  
Anodic Polarization ◽  
Point Of View ◽  
Alkaline Solutions ◽  
Inorganic Polymers ◽  
Electrolytic Oxidation ◽  
Plasma Electrolytic ◽  
Peo Coatings ◽  
First Time

In this review, the main kinetics and mechanism regularities of plasma electrolytic oxidation (PEO) of aluminum alloys are discussed. The material and heat balances of the PEO process, including anomalous gas evolution and possible thermochemical reactions are presented for the first time. Side effects accompanying spark discharges from both the surface and the electrolyte sides are analyzed. The influences of electrical regime (direct, alternative, and pulse current) on the rate of coatings growth are summarized from the electrochemical point of view. Different modes of anodic polarization and electrolyte composition (alkaline solutions with inorganic polymers and dispersed constituents) are discussed in the applicative aspect.

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