Plasma Electrolytic Oxidation and Characterization of Spark Plasma Sintered Magnesium/Hydroxyapatite Composites

2013 ◽  
Vol 765 ◽  
pp. 827-831 ◽  
Author(s):  
R. Viswanathan ◽  
N. Rameshbabu ◽  
Sarangapani Kennedy ◽  
D. Sreekanth ◽  
K. Venkateswarlu ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Plasma Electrolytic Oxidation ◽  
Test Results ◽  
X Ray Diffraction ◽  
Morphological Studies ◽  
Plasma Sintering ◽  
Electrolytic Oxidation ◽  
Spark Plasma ◽  
Plasma Electrolytic

Magnesium (Mg)/hydroxyapatite (HA) (10 wt.% and 20 wt.%) composites were prepared by using pure Mg and as synthesized HA powders using the spark plasma sintering (SPS) method. The objective of the present study is to improve the corrosion resistance of spark plasma sintered Mg/HA composites and to ensure that the degradation time of these composites match with that of bone remodeling. Mg and HA powders were ball milled for 2 h and spark plasma sintered at a temperature of 475 °C and pressure of 40 MPa in vacuum. The sintered compacts were further treated by plasma electrolytic oxidation (PEO) in order to improve the corrosion resistance. The structural, microstructural and morphological studies were done using X-ray diffraction, optical microscopy and scanning electron microscopy, respectively. The corrosion resistance of as-sintered and PEO treated Mg/HA composites was studied by potentiodynamic polarization test in a 7.4 pH simulated body fluid (SBF) environment. The corrosion test results of as-sintered composites showed that the corrosion resistance decreases with the increase in percentage of HA in the composite. However, the PEO treated Mg/HA composites have shown delayed onset of degradation. Therefore, it can be hypothesized that the PEO treated Mg/HA composites would serve as bioactive and biodegradable orthopedic implant materials with low corrosion rates.

scholarly journals Fabrication and Characterization of Ceramic Coating on Al7075 Alloy by Plasma Electrolytic Oxidation in Molten Salt

Coatings ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 993
Author(s):  
Alexander Sobolev ◽  
Tamar Peretz ◽  
Konstantin Borodianskiy
Keyword(s):  
Corrosion Resistance ◽  
Molten Salt ◽  
Plasma Electrolytic Oxidation ◽  
Ceramic Coating ◽  
Electrochemical Impedance ◽  
Current Frequency ◽  
Electrolytic Oxidation ◽  
Fabrication And Characterization ◽  
Plasma Electrolytic

The fabrication of a ceramic coating on the metallic substrate is usually applied to achieve the improved performance of the material. Plasma electrolytic oxidation (PEO) is one of the most promising methods to reach this performance, mostly wear and corrosion resistance. Traditional PEO is carried out in an aqueous electrolyte. However, the current work showed the fabrication and characterization of a ceramic coating using PEO in molten salt which was used to avoid disadvantages in system heating-up and the formation of undesired elements in the coating. Aluminum 7075 alloy was subjected to the surface treatment using PEO in molten nitrate salt. Various current frequencies were applied in the process. Coating investigations revealed its surface porous structure and the presence of two oxide layers, α-Al2O3 and γ-Al2O3. Microhardness measurements and chemical and phase examinations confirmed these results. Potentiodynamic polarization tests and electrochemical impedance spectroscopy revealed the greater corrosion resistance for the coated alloy. Moreover, the corrosion resistance was increased with the current frequency of the PEO process.

scholarly journals Microstructure and phase composition of surface layers formed on aluminium alloys by plasma electrolytic oxidation

2020 ◽  
Vol 30 (1) ◽  
pp. 1-6
Author(s):  
Maria-Magdalena DICU ◽  
◽  
Paul-Costinel DICU
Keyword(s):  
Aluminium Alloys ◽  
Plasma Electrolytic Oxidation ◽  
Sodium Metasilicate ◽  
X Ray Diffraction ◽  
Surface Layers ◽  
X Ray ◽  
Electrolytic Oxidation ◽  
Plasma Electrolytic ◽  
Xrd Techniques

This paper presents elaboration and structural characterization of surface layers formed on aluminumalloys by plasma electrolytic oxidation (PEO). The electrolyte is a mixture consisting: sodium metasilicate and sodium hydroxide. The coatings obtained by PEO were investigated with: scanning electron microscopy (SEM) with Energy dispersive X-ray spectrometer (EDX) and X-ray diffraction (XRD)techniques.

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.

MICROSTRUCTURES AND ABRASIVE PROPERTIES OF THE OXIDE COATINGS ON Al6061 ALLOYS PREPARED BY PLASMA ELECTROLYTIC OXIDATION IN DIFFERENT ELECTROLYTES

2010 ◽  
Vol 17 (03) ◽  
pp. 271-276
Author(s):  
KAI WANG ◽  
SANGSIK BYUN ◽  
CHAN GYU LEE ◽  
BON HEUN KOO ◽  
YI QI WANG ◽  
...  
Keyword(s):  
Plasma Electrolytic Oxidation ◽  
Wear Test ◽  
Xrd Analysis ◽  
Test Results ◽  
X Ray Diffraction ◽  
Abrasive Resistance ◽  
Electrolytic Oxidation ◽  
Abrasive Properties ◽  
Coating Microstructure ◽  
Plasma Electrolytic

Al 2 O 3 coatings were prepared on T6-tempered Al6061 alloys substrate under a hybrid voltage (AC 200 V–60 Hz and DC 260 V value) by plasma electrolytic oxidation (PEO) in 30 min. The effects of different electrolytes on the abrasive behaviors of the coatings were studied by conducting dry ball-on-disk wear tests. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to investigate the coating microstructure. XRD analysis results show that the coatings mainly consist of α- and γ- Al 2 O 3, and some mullite and AlPO 4 phase in Na 2 SiO 3 and Na 3 PO 4 containing electrolytes, respectively. The wear test results show that the coatings which were PEO-treated in Na 3 PO 4 containing electrolyte presented the most excellent abrasive resistance property.

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 Surface Modification of Aluminum 6061-O Alloy by Plasma Electrolytic Oxidation to Improve Corrosion Resistance Properties

Coatings ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 4
Author(s):  
Dmitry V. Dzhurinskiy ◽  
Stanislav S. Dautov ◽  
Petr G. Shornikov ◽  
Iskander Sh. Akhatov
Keyword(s):  
Corrosion Resistance ◽  
Aluminum Alloy ◽  
Aluminum Alloys ◽  
Plasma Electrolytic Oxidation ◽  
Electrochemical Impedance ◽  
High Strength ◽  
Electrolytic Oxidation ◽  
Coating Layers ◽  
Plasma Electrolytic ◽  
High Strength Aluminum Alloys

In the present investigation, the plasma electrolytic oxidation (PEO) process was employed to form aluminum oxide coating layers to enhance corrosion resistance properties of high-strength aluminum alloys. The formed protective coating layers were examined by means of scanning electron microscopy (SEM) and characterized by several electrochemical techniques, including open circuit potential (OCP), linear potentiodynamic polarization (LP) and electrochemical impedance spectroscopy (EIS). The results were reported in comparison with the bare 6061-O aluminum alloy to determine the corrosion performance of the coated 6061-O alloy. The PEO-treated aluminum alloy showed substantially higher corrosion resistance in comparison with the untreated substrate material. A relationship was found between the coating formation stage, process parameters and the thickness of the oxide-formed layers, which has a measurable influence on enhancing corrosion resistance properties. This study demonstrates promising results of utilizing PEO process to enhance corrosion resistance properties of high-strength aluminum alloys and could be recommended as a method used in industrial applications.

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.

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