scholarly journals Plasma Electrolytic Oxidation of Magnesium Alloy AZ31B in Electrolyte Containing Al2O3 Sol as Additives

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1618 ◽  
Author(s):  
Xiaohua Tu ◽  
Chengping Miao ◽  
Yang Zhang ◽  
Yaling Xu ◽  
Jiayou Li
Keyword(s):  
Corrosion Resistance ◽  
Plasma Electrolytic Oxidation ◽  
X Ray Diffraction ◽  
Peak Intensity ◽  
Magnesium Alloy Az31b ◽  
Electrolytic Oxidation ◽  
Microhardness Testing ◽  
Alkaline Electrolytes ◽  
Plasma Electrolytic ◽  
Peo Coatings

Plasma electrolytic oxidation (PEO) coatings were produced on AZ31B magnesium alloys in alkaline electrolytes with the addition of various concentrations of Al2O3 sols. Effects of Al2O3 sol concentrations on the microstructure, phase composition, corrosion resistance and hardness of PEO coatings were evaluated by scanning electron microscopy (SEM), X-ray diffraction (XRD), microhardness testing and potentiodynamic polarization measurements, respectively. It was revealed that the Al2O3 sol mostly participated in the formation of the ceramic coating and transferred into the MgAl2O4 phase. With the increase of the Al2O3 sol concentration in the range of 0–6 vol%, the coating performance in terms of the microstructure, diffraction peak intensity of the MgAl2O4 phase, corrosion resistance and microhardness was improved. Further increase of Al2O3 sol addition did not generate better results. This indicated that 6 vol% might be the proper Al2O3 sol concentration for the formation of PEO coatings.

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.

Nanocrystallites in the Pores and Magnetic Properties of PEO Coatings

2015 ◽  
Vol 245 ◽  
pp. 190-194 ◽  
Author(s):  
V.S. Rudnev ◽  
I.V. Lukiyanchuk ◽  
M.V. Adigamova ◽  
V.P. Morozova ◽  
I.A. Tkachenko
Keyword(s):  
Magnetic Properties ◽  
Plasma Electrolytic Oxidation ◽  
Nickel Acetate ◽  
Iron Oxalate ◽  
Electrolytic Oxidation ◽  
Alkaline Electrolytes ◽  
Plasma Electrolytic ◽  
Peo Coatings

The coatings manifesting ferromagnetic characteristics have been formed on titanium and aluminum by plasma electrolytic oxidation (PEO) in alkaline electrolytes additionally containing iron oxalate and cobalt or nickel acetate. The metals of iron subgroup are found to be concentrated in pores of PEO coatings, as a rule, in form of crystallites. In a number of cases the relation between crystallite compositions and magnetic properties of the coatings has been established.

MICROSTRUCTURE AND WEARING PROPERTIES OF PEO COATINGS: EFFECTS OF Al2O3 AND TiO2

2018 ◽  
Vol 25 (05) ◽  
pp. 1850102 ◽  
Author(s):  
Y. ZHANG ◽  
W. FAN ◽  
H. Q. DU ◽  
Y. W. ZHAO
Keyword(s):  
Photoelectron Spectroscopy ◽  
Plasma Electrolytic Oxidation ◽  
Xps Analysis ◽  
X Ray Diffraction ◽  
Properties Of Coatings ◽  
X Ray ◽  
Electrolytic Oxidation ◽  
Plasma Electrolytic ◽  
Peo Coatings ◽  
Scanning Electron

Plasma electrolytic oxidation (PEO) coatings were formed on aluminium alloy in additive Al2O3- and TiO2-containing Na2SiO3-based electrolytes, respectively. The effect of these additives on morphology, composition and wearing properties of coatings was investigated. The morphology and composition of coatings were studied by means of scanning electron microscopy (SEM) and X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS). Analysis of wearing properties of coatings were done by friction and wearing experiment. It was found that the use of additives greatly affects the surface morphology of coatings. It is shown that the content of [Formula: see text]-Al2O3 in coatings formed in Al2O3-containing electrolytes increased with the addition of Al2O3. However, the content of [Formula: see text]-Al2O3 in coatings formed in TiO2-containing electrolytes first increased and then decreased. Among these coatings, the coating formed in silicate-based electrolytes system containing 7[Formula: see text]g/L Al2O3 showed the most superior wearing properties.

scholarly journals Wear and Corrosion Resistance of Plasma Electrolytic Oxidation Coatings on 6061 Al Alloy in Electrolytes with Aluminate and Phosphate

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4037
Author(s):  
Zhenjun Peng ◽  
Hui Xu ◽  
Siqin Liu ◽  
Yuming Qi ◽  
Jun Liang
Keyword(s):  
Corrosion Resistance ◽  
Plasma Electrolytic Oxidation ◽  
Salt Spray ◽  
P Element ◽  
Alumina Coating ◽  
Al Alloy ◽  
Wear Properties ◽  
Electrolytic Oxidation ◽  
Plasma Electrolytic ◽  
Peo Coatings

Phosphate and aluminate electrolytes were used to prepare plasma electrolytic oxidation (PEO) coatings on 6061 aluminum alloy. The surface and cross-section microstructure, element distribution, and phase composition of the PEO coatings were characterized by SEM, EDS, XPS, and XRD. The friction and wear properties were evaluated by pin-on-disk sliding tests under dry conditions. The corrosion resistance of PEO coatings was investigated by electrochemical corrosion and salt spray tests in acidic environments. It was found that the PEO coatings prepared from both phosphate and aluminate electrolytes were mainly composed of α-Al2O3 and γ-Al2O3. The results demonstrate that a bi-layer coating is formed in the phosphate electrolyte, and a single-layered dense alumina coating with a hardness of 1300 HV is realizable in the aluminate electrolyte. The aluminate PEO coating had a lower wear rate than the phosphate PEO coating. However, the phosphate PEO coating showed a better corrosion resistance in acidic environment, which is mainly attributed to the presence of an amorphous P element at the substrate/coating interface.

scholarly journals Special Issue: Plasma Electrolytic Oxidation (PEO) Coatings

Coatings ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 111
Author(s):  
Marta Mohedano ◽  
Beatriz Mingo
Keyword(s):  
Corrosion Resistance ◽  
Plasma Electrolytic Oxidation ◽  
Special Issue ◽  
Wear Properties ◽  
Technological Society ◽  
Good Corrosion Resistance ◽  
Functionalized Surfaces ◽  
Electrolytic Oxidation ◽  
Plasma Electrolytic ◽  
Peo Coatings

The demand of modern technological society for light structural materials (Al, Ti, Mg) emphasizes a combination of good corrosion resistance with wear properties and functionalized surfaces [...]

scholarly journals Plasma Electrolytic Oxidation Treatment of Zr-2.5%Nb Alloy for Corrosion Resistance Enhancement

2019 ◽  
Vol 69 (12) ◽  
pp. 3490-3493
Author(s):  
Elisabeta Coaca ◽  
Alexandru Marin ◽  
Oana Rusu ◽  
Viorel Malinovschi ◽  
Victor Andrei
Keyword(s):  
Corrosion Resistance ◽  
Plasma Electrolytic Oxidation ◽  
Aqueous Electrolyte ◽  
Oxide Coating ◽  
Electrolyte Solutions ◽  
X Ray Diffraction ◽  
Oxidation Treatment ◽  
X Ray ◽  
Electrolytic Oxidation ◽  
Plasma Electrolytic

Anticorrosion layers were prepared on commercial Zr-2.5%Nb alloy by employing plasma electrolytic oxidation (PEO) process in aqueous electrolyte solutions. Microstructure and electrochemical behavior were evaluated using X-ray diffraction (XRD), optical metallography and potentiodynamic polarization measurements. The obtained coatings are uneven, presenting a dominant monoclinic crystallographic phase of ZrO2. Enhanced corrosion resistance was attributed to the PEO-treated samples compared to the commercial black oxide coating.

scholarly journals Effect of Applied Current Density of Plasma Electrolytic Oxidation Process on Corrosion Resistance of AZ31 Magnesium Alloy

2019 ◽  
Vol 21 (2) ◽  
pp. 32-36 ◽  
Author(s):  
Daniel Kajanek ◽  
Branislav Hadzima ◽  
Matej Brezina ◽  
Martina Jackova
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Current Density ◽  
Plasma Electrolytic Oxidation ◽  
Az31 Magnesium Alloy ◽  
Applied Current ◽  
Applied Current Density ◽  
Electrolytic Oxidation ◽  
Plasma Electrolytic ◽  
Peo Coatings

Impact of applied current density during the plasma electrolytic oxidation (PEO) process on corrosion resistance of AZ31 magnesium alloy was studied. The PEO coatings were prepared using four different current densities with values of 0.025 A/cm2, 0.05 A/cm2, 0.1 A/cm2 and 0.15 A/cm2 in electrolyte consisting of 10 g/l Na 3PO4.12H2O and 1 g/l KOH. Morphology and chemical composition of the coatings was examined using the scanning electron microscopy and EDS analysis respectively. Electrochemical characteristics of ground and coated samples were measured by means of electrochemical impedance spectroscopy (EIS) in 0.1M NaCl solution. Obtained data in form of Nyquist diagrams were analysed by equivalent circuit method. Results of experiments showed that value of applied current density had significant effect on protective performance of the PEO coatings prepared on AZ31 magnesium alloy surface.

Titanium carbide’s effects on coatings formed on D16T aluminum alloy by plasma electrolytic oxidation

2020 ◽  
Vol 67 (1) ◽  
pp. 48-58
Author(s):  
Wanying Liu ◽  
Junjie Yang ◽  
Yuhong Qiu ◽  
Ying Liu ◽  
Kuanhai Deng
Keyword(s):  
Corrosion Resistance ◽  
Aluminum Alloy ◽  
Titanium Carbide ◽  
Plasma Electrolytic Oxidation ◽  
Ceramic Coatings ◽  
Content Type ◽  
X Ray ◽  
Electrolytic Oxidation ◽  
Plasma Electrolytic ◽  
Peo Coatings

Purpose The preferable concentration of titanium carbide was optimized and added as an additive to the micro-arc oxidation electrolyte to produce a high corrosion-resistant coating on D16T aluminum alloy. Design/methodology/approach Ceramic coatings were deposited on D16T aluminum alloy by plasma electrolytic oxidation in alkaline silicate electrolytes with micron titanium carbide particle suspending at different concentrations. Influences of additive concentration on morphology, elemental and phase composition and corrosion resistance of doped PEO coatings were evaluated by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) and electrochemical methods, respectively. Findings Results revealed that suspending titanium carbide additives incorporated into ceramic coatings through discharging channels and chemically transformed into amorphous stage. The content of titanium in the doped coatings increased with the increasing concentration of suspending micron additive. Compared with the coating without particle addition, the corrosion resistance of the coating produced in 8 g/L titanium carbide suspension increased more than 20 times. The result indicated that the incorporation of titanium into the PEO coatings formed on the D16T aluminum alloy could effectively improve the corrosion resistance. Originality/value The mechanism of corporation of TiC and the mechanism of improving the corrosion resistance of the coating were proposed.

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