scholarly journals Plasma electrolytic oxidation of tantalum

2012 ◽  
Vol 9 (1) ◽  
pp. 81-94 ◽  
Author(s):  
Marija Petkovic ◽  
Stevan Stojadinovic ◽  
Rastko Vasilic ◽  
Ivan Belca ◽  
Becko Kasalica ◽  
...  
Keyword(s):  
Plasma Electrolytic Oxidation ◽  
Optical Emission ◽  
Oxide Coating ◽  
Oxide Coatings ◽  
Tungstosilicic Acid ◽  
Coating Morphology ◽  
Electrolytic Oxidation ◽  
Plasma Electrolytic ◽  
Peo Coatings

This paper is a review of our research on the plasma electrolytic oxidation (PEO) process of tantalum in 12-tungstosilicic acid. For the characterization of microdischarges during PEO, real-time imaging and optical emission spectroscopy (OES) were used. The surface morphology, chemical and phase composition of oxide coatings were investigated by AFM, SEM-EDS and XRD. Oxide coating morphology is strongly dependent on PEO time. The elemental components of PEO coatings are Ta, O, Si and W. The oxide coatings are partly crystallized and mainly composed of WO3, Ta2O5 and SiO2.

Characterization of Coating Morphology and Heat-Resistance in Plasma Electrolytic Oxidation of Magnesium Alloy

2007 ◽  
Vol 561-565 ◽  
pp. 2459-2463 ◽  
Author(s):  
Li Shi Wang ◽  
Chun Xu Pan ◽  
Qi Zhou Cai ◽  
Bo Kang Wei
Keyword(s):  
Heat Resistance ◽  
Plasma Electrolytic Oxidation ◽  
Az91d Alloy ◽  
Excellent Thermal Stability ◽  
Air Atmosphere ◽  
Coating Morphology ◽  
Electrolytic Oxidation ◽  
Plasma Electrolytic ◽  
Peo Coatings

This paper reports the heat-resistance of plasma electrolytic oxidation (PEO) coatings formed on AZ91D alloy in phosphate electrolytes (P-film) and silicate electrolytes (Si-film). The results showed that the P-film was mainly composed of MgAl2O4, MgO and the Si-film was composed of Mg2SiO4, MgO. Thermoanalysis results verified that all these phases contained in the two type coatings had excellent thermal stability below 800oC. Meanwhile, the total area of heat erosion formed on the surface of samples tended to be increased with the exposure time prolonged in high temperature (410 oC and air atmosphere).

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 Spectroscopic study of micro-discharges during plasma electrolytic oxidation of Al-Zn-Si alloy

2019 ◽  
Vol 84 (8) ◽  
pp. 915-923 ◽  
Author(s):  
Stevan Stojadinovic ◽  
Rastko Vasilic
Keyword(s):  
Plasma Electrolytic Oxidation ◽  
Water Solution ◽  
Oxide Coating ◽  
Sodium Metasilicate ◽  
Plasma Electron ◽  
Constant Current ◽  
Oxide Coatings ◽  
Constant Current Density ◽  
Electrolytic Oxidation ◽  
Plasma Electrolytic

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.

scholarly journals Plasma electrolytic oxidation of metals

2013 ◽  
Vol 78 (5) ◽  
pp. 713-716 ◽  
Author(s):  
Stevan Stojadinovic
Keyword(s):  
Photoelectron Spectroscopy ◽  
Plasma Electrolytic Oxidation ◽  
Dielectric Breakdown ◽  
Optical Emission ◽  
Active Surface ◽  
Spatial Density ◽  
Oxide Coatings ◽  
X Ray ◽  
Electrolytic Oxidation ◽  
Plasma Electrolytic

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.

Study on coating growth characteristics during the electrolytic oxidation of a magnesium–lithium alloy by optical emission spectroscopy analysis

RSC Advances ◽  
2015 ◽  
Vol 5 (84) ◽  
pp. 68806-68814 ◽  
Author(s):  
Zhongping Yao ◽  
Qixing Xia ◽  
Han Wei ◽  
Dongqi Li ◽  
Qiu Sun ◽  
...  
Keyword(s):  
Emission Spectroscopy ◽  
Plasma Electrolytic Oxidation ◽  
Optical Emission Spectroscopy ◽  
Optical Emission ◽  
Growth Characteristics ◽  
Spectroscopy Analysis ◽  
Electrolytic Oxidation ◽  
Composition Structure ◽  
Plasma Electrolytic ◽  
Peo Coatings

The aim of this study is to analyze the composition, structure and growth characteristics of plasma electrolytic oxidation (PEO) coatings through optical emission spectroscopy (OES).

scholarly journals Formation and Properties of Oxide Coatings with Immobilized Zeolites Obtained by Plasma Electrolytic Oxidation of Aluminum

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1241
Author(s):  
Kristina Mojsilović ◽  
Uroš Lačnjevac ◽  
Srna Stojanović ◽  
Ljiljana Damjanović-Vasilić ◽  
Stevan Stojadinović ◽  
...  
Keyword(s):  
Plasma Electrolytic Oxidation ◽  
Processing Time ◽  
Water Solution ◽  
Activity Levels ◽  
Oxide Coatings ◽  
X Ray ◽  
Electrolytic Oxidation ◽  
Chemical And Phase Compositions ◽  
Plasma Electrolytic ◽  
Peo Coatings

In this paper, we employed plasma electrolytic oxidation (PEO) of aluminum in a water solution of sodium tungstate (Na2WO4∙2H2O) with the addition of the pure and Ce-loaded zeolites clinoptilolite and 13 X for the preparation of oxide coatings. The obtained coatings were characterized with respect to their morphologies and chemical and phase compositions using scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy, atomic force microscopy, and X-ray diffraction. The prepared coatings contained γ-alumina, WO3, and metallic tungsten. The surface morphologies of the obtained coatings strongly depended on the PEO processing time; the roughness of all coatings increased with PEO time, while porosity decreased with PEO processing time as a result of microdischarge coalescence and growth. All coatings contained elements originating from the substrate and from the electrolytes. Coatings containing zeolites with Ce showed higher photoactivity than those with immobilized pure zeolites. The highest photocatalytic activity levels were observed for coatings containing immobilized Ce-exchanged clinoptilolite processed for 10 min. It was observed that both clinoptilolite and 13X zeolites improved the features of the PEO coatings in a similar manner, making natural and abundant clinoptilolite an excellent candidate for various applications.

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