scholarly journals Impact of processing parameters in plasma electrolytic oxidation on corrosion resistance of magnesium alloy type AZ91

2021 ◽  
Author(s):  
Talal A. Aljohani ◽  
Sami Aljadaan ◽  
Meteb T. Bin Rubayan ◽  
Fuad Khoshnaw
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Plasma Electrolytic Oxidation ◽  
Processing Parameters ◽  
Alloy Type ◽  
Electrolytic Oxidation ◽  
Plasma Electrolytic

scholarly journals Impact of Processing Parameters in Plasma Electrolytic Oxidation (PEM) on Corrosion Resistance of Magnesium Alloy Type AZ91

2021 ◽  
Author(s):  
Talal Aljohani ◽  
Sami Aljadaan ◽  
Meteb Bin Rubayan ◽  
Fuad Khoshnaw
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Duty Cycle ◽  
Plasma Electrolytic Oxidation ◽  
Electrochemical Impedance ◽  
Processing Parameters ◽  
Coated Sample ◽  
Alloy Type ◽  
Electrolytic Oxidation ◽  
Plasma Electrolytic

This study aims to investigate the effect of the processing parameters in plasma electrolytic oxidation (PEO) on the corrosion resistance of magnesium alloy type AZ91. The PEO coatings were prepared on the samples using alkaline-based electrolyte. Both unipolar and bipolar, different frequencies and duty cycles were applied. Corrosion tests, using potentiodynamic polarisation (PDP), linear and cyclic, and electrochemical impedance spectroscopy (EIS) techniques, were applied on the as-received and PEO coated samples. Scanning electron microscopy was used to investigate the surface morphology, e.g. micropores, as well as to measure the thickness of the coated layer with changing the processing parameters. The results show that the size of micropores is interrelated to the duty cycle percentage and current polarities, as the higher frequency causes thinner coating layers, with fewer micropores, consequently higher corrosion resistance. In addition, increasing the duty cycle, a denser and more compact coating was obtained. The XRD results showed missing peak of the α-Mg phase in a PEO coated sample using Bipolar, the highest frequency (1666 Hz) and the highest duty cycle (66.6%). The mils per year calculations showed that the PEO coated have lower corrosion rate by at least 8 times than the as-received alloy.

scholarly journals Effect of alcohol addition on the structure and corrosion resistance of plasma electrolytic oxidation films formed on AZ31B magnesium alloy

RSC Advances ◽  
2020 ◽  
Vol 10 (15) ◽  
pp. 9026-9036
Author(s):  
Hidetaka Asoh ◽  
Kento Asakura ◽  
Hideki Hashimoto
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Plasma Electrolytic Oxidation ◽  
Az31b Magnesium Alloy ◽  
Electrolytic Oxidation ◽  
Plasma Electrolytic

Alcohol used as an additive could act not only as a leveler for the formation of compact film but also as an enhancer for film qualities, such as corrosion resistance and withstand voltage.

scholarly journals TiO2Deposition on AZ31 Magnesium Alloy Using Plasma Electrolytic Oxidation

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Leon White ◽  
Youngmi Koo ◽  
Yeoheung Yun ◽  
Jagannathan Sankar
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Plasma Electrolytic Oxidation ◽  
Electrochemical Impedance ◽  
Protective Layer ◽  
Az31 Magnesium Alloy ◽  
Treatment Technique ◽  
Functional Coating ◽  
Electrolytic Oxidation ◽  
Plasma Electrolytic

Plasma electrolytic oxidation (PEO) has been used in the past as a useful surface treatment technique to improve the anticorrosion properties of Mg alloys by forming protective layer. Coatings were prepared on AZ31 magnesium alloy in phosphate electrolyte with the addition of TiO2nanoparticles using plasma electrolytic oxidation (PEO). This present work focuses on developing a TiO2functional coating to create a novel electrophotocatalyst while observing the surface morphology, structure, composition, and corrosion resistance of the PEO coating. Microstructural characterization of the coating was investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM) followed by image analysis and energy dispersive spectroscopy (EDX). The corrosion resistance of the PEO treated samples was evaluated with electrochemical impedance spectroscopy (EIS) and DC polarization tests in 3.5 wt.% NaCl. The XRD pattern shows that the components of the oxide film include Mg from the substrate as well as MgO and Mg2TiO4due to the TiO2nanoparticle addition. The results show that the PEO coating with TiO2nanoparticles did improve the corrosion resistance when compared to the AZ31 substrate alloy.

scholarly journals Magnesium Alloy Effects on Plasma Electrolytic Oxidation Electro-Ceramic and Electro-Coat Formation and Corrosion Resistance

2019 ◽  
Vol 166 (14) ◽  
pp. C492-C508 ◽  
Author(s):  
Michael P. Brady ◽  
Donovan N. Leonard ◽  
Elizabeth A. McNally ◽  
Joseph R. Kish ◽  
Harry M. Meyer ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Plasma Electrolytic Oxidation ◽  
Electrolytic Oxidation ◽  
Plasma Electrolytic

Influence of Plasma Electrolytic Oxidation coating on corrosion characteristics of Friction Stir Welded ZE41 rare earth Magnesium alloy

2021 ◽  
Author(s):  
N Sivashanmugam ◽  
KL Harikrishna ◽  
S R Koteswara Rao ◽  
N Rameshbabu ◽  
P Manojkumar
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Rare Earth ◽  
Magnesium Alloy ◽  
Plasma Electrolytic Oxidation ◽  
Dense Layer ◽  
Metallographic Examination ◽  
Friction Stir ◽  
Electrolytic Oxidation ◽  
Plasma Electrolytic

Abstract Magnesium and its alloys are extensively used in the defence, aerospace and automotive industries, owing to their excellent mechanical properties. But there is a requirement of corrosion prevention treatment before using it for applications, since the corrosion resistance of Mg alloy is poor. In this work, a study on the mechanical properties of friction stir welded ZE41 rare earth magnesium alloy thick plates of 15mm and 25mm, was carried out. A metallographic examination and mechanical tests were conducted on both the welds. Furthermore, Plasma Electrolytic Oxidation (PEO), a surface conversion treatment was carried out on both the base material as well as on the friction stir butt joints. X-ray diffraction and scanning electron microscopy analysis were carried out on all the samples, with and without coating. The coated and uncoated samples were assessed by potentiodynamic polarisation (PDP) tests and electrochemical impedance spectroscopy (EIS) to study the electrochemical corrosion behaviour. An outer porous layer and an inner dense layer, have been identified from the SEM images. From the corrosion tests results it was revealed that there was an improvement in the corrosion resistance of both the base metal as well as the weldments by the PEO coating process.

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