Plasma Electrolytic Oxidation Treatment of AZ31 Magnesium Alloy for Biomedical Applications: The Influence of Applied Current on Corrosion Resistance and Surface Characteristics

Magnesium alloys are an exciting challenge for the biomaterials field given their well-established biodegradability and biocompatibility. However, when exposed to biological fluids, their rapid degradation and hydrogen release are the main drawbacks for clinical applications. This work aimed to inve...

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Main Authors: Annalisa Acquesta, Pietro Russo, Tullio Monetta
Format: Article
Language:English
Published: MDPI AG 2023-03-01
Series:Crystals
Subjects:
Online Access:https://www.mdpi.com/2073-4352/13/3/510
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author Annalisa Acquesta
Pietro Russo
Tullio Monetta
author_facet Annalisa Acquesta
Pietro Russo
Tullio Monetta
author_sort Annalisa Acquesta
collection DOAJ
description Magnesium alloys are an exciting challenge for the biomaterials field given their well-established biodegradability and biocompatibility. However, when exposed to biological fluids, their rapid degradation and hydrogen release are the main drawbacks for clinical applications. This work aimed to investigate the influence of the current density applied during the plasma electrolytic oxidation (PEO) treatment on the durability of an AZ31 magnesium alloy. In particular, specific interest was directed to the degradation rate undergone by the PEO coating, obtained under two different current density conditions, when exposed to Hank’s solution at 37 °C to simulate the physiological environment, employing the techniques of potentiodynamic polarization and electrochemical impedance spectroscopy. Experimental results highlighted that the plasma electrolytic oxidation technique resulted in an improvement in the corrosion resistance of the magnesium alloy in the test solution. The current density affected the morphology of the coating. In particular, the anodic oxide coating obtained by applying the highest current density showed a higher thickness and fewer but larger pores, while the lowest current density generated a thinner PEO coating characterized by several but smaller pores. Surprisingly, the best corrosion resistance has been exhibited by the anodic oxide coating grown at the highest current density.
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spelling doaj.art-e1c128599ae0445480c2b01fefd2219e2023-11-17T10:29:46ZengMDPI AGCrystals2073-43522023-03-0113351010.3390/cryst13030510Plasma Electrolytic Oxidation Treatment of AZ31 Magnesium Alloy for Biomedical Applications: The Influence of Applied Current on Corrosion Resistance and Surface CharacteristicsAnnalisa Acquesta0Pietro Russo1Tullio Monetta2Department of Chemical Engineering, Materials and Industrial Production, University of Napoli Federico II, Piazzale Tecchio 80, 80125 Napoli, ItalyInstitute for Polymers, Composites and Biomaterials, National Research Council, 80078 Pozzuoli, ItalyDepartment of Chemical Engineering, Materials and Industrial Production, University of Napoli Federico II, Piazzale Tecchio 80, 80125 Napoli, ItalyMagnesium alloys are an exciting challenge for the biomaterials field given their well-established biodegradability and biocompatibility. However, when exposed to biological fluids, their rapid degradation and hydrogen release are the main drawbacks for clinical applications. This work aimed to investigate the influence of the current density applied during the plasma electrolytic oxidation (PEO) treatment on the durability of an AZ31 magnesium alloy. In particular, specific interest was directed to the degradation rate undergone by the PEO coating, obtained under two different current density conditions, when exposed to Hank’s solution at 37 °C to simulate the physiological environment, employing the techniques of potentiodynamic polarization and electrochemical impedance spectroscopy. Experimental results highlighted that the plasma electrolytic oxidation technique resulted in an improvement in the corrosion resistance of the magnesium alloy in the test solution. The current density affected the morphology of the coating. In particular, the anodic oxide coating obtained by applying the highest current density showed a higher thickness and fewer but larger pores, while the lowest current density generated a thinner PEO coating characterized by several but smaller pores. Surprisingly, the best corrosion resistance has been exhibited by the anodic oxide coating grown at the highest current density.https://www.mdpi.com/2073-4352/13/3/510AZ31biodegradable alloyplasma electrolytic oxidationcorrosionphysiological environment
spellingShingle Annalisa Acquesta
Pietro Russo
Tullio Monetta
Plasma Electrolytic Oxidation Treatment of AZ31 Magnesium Alloy for Biomedical Applications: The Influence of Applied Current on Corrosion Resistance and Surface Characteristics
Crystals
AZ31
biodegradable alloy
plasma electrolytic oxidation
corrosion
physiological environment
title Plasma Electrolytic Oxidation Treatment of AZ31 Magnesium Alloy for Biomedical Applications: The Influence of Applied Current on Corrosion Resistance and Surface Characteristics
title_full Plasma Electrolytic Oxidation Treatment of AZ31 Magnesium Alloy for Biomedical Applications: The Influence of Applied Current on Corrosion Resistance and Surface Characteristics
title_fullStr Plasma Electrolytic Oxidation Treatment of AZ31 Magnesium Alloy for Biomedical Applications: The Influence of Applied Current on Corrosion Resistance and Surface Characteristics
title_full_unstemmed Plasma Electrolytic Oxidation Treatment of AZ31 Magnesium Alloy for Biomedical Applications: The Influence of Applied Current on Corrosion Resistance and Surface Characteristics
title_short Plasma Electrolytic Oxidation Treatment of AZ31 Magnesium Alloy for Biomedical Applications: The Influence of Applied Current on Corrosion Resistance and Surface Characteristics
title_sort plasma electrolytic oxidation treatment of az31 magnesium alloy for biomedical applications the influence of applied current on corrosion resistance and surface characteristics
topic AZ31
biodegradable alloy
plasma electrolytic oxidation
corrosion
physiological environment
url https://www.mdpi.com/2073-4352/13/3/510
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AT pietrorusso plasmaelectrolyticoxidationtreatmentofaz31magnesiumalloyforbiomedicalapplicationstheinfluenceofappliedcurrentoncorrosionresistanceandsurfacecharacteristics
AT tulliomonetta plasmaelectrolyticoxidationtreatmentofaz31magnesiumalloyforbiomedicalapplicationstheinfluenceofappliedcurrentoncorrosionresistanceandsurfacecharacteristics