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Impact of Processing Parameters in Plasma Electrolytic Oxidation (PEM) on Corrosion Resistance of Magnesium Alloy Type AZ91
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  • Talal Aljohani,
  • Sami Aljadaan,
  • Meteb Bin Rubayan,
  • Fuad Khoshnaw
Talal Aljohani

Corresponding Author:[email protected]

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Sami Aljadaan
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Meteb Bin Rubayan
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Fuad Khoshnaw
De Montfort University
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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.
06 Apr 2021Submitted to Engineering Reports
07 Apr 2021Submission Checks Completed
07 Apr 2021Assigned to Editor
08 Apr 2021Reviewer(s) Assigned
14 Jun 20211st Revision Received
18 Jun 2021Assigned to Editor
18 Jun 2021Submission Checks Completed
21 Jun 2021Reviewer(s) Assigned
19 Jul 2021Editorial Decision: Revise Major
03 Aug 20212nd Revision Received
04 Aug 2021Submission Checks Completed
04 Aug 2021Assigned to Editor
08 Aug 2021Reviewer(s) Assigned
23 Aug 2021Editorial Decision: Revise Minor
23 Aug 20213rd Revision Received
24 Aug 2021Assigned to Editor
24 Aug 2021Submission Checks Completed
30 Aug 2021Editorial Decision: Accept
Feb 2022Published in Engineering Reports volume 4 issue 2. 10.1002/eng2.12459