New insights on the influence of low frequency pulsed current on the characteristics of PEO coatings formed on AZ31B

L. Toro, A. A. Zuleta, E. Correa, D. Calderón, Y. Galindez, J. Calderón, P. Chacón, A. Valencia-Escobar, F. Echeverría E

Resultado de la investigación: Contribución a una revistaArtículo

Resumen

In this work, anodic oxide layers on the surface of an AZ31 magnesium alloy were obtained by plasma electrolytic oxidation (PEO) process under low frequency pulsed current. For this, electrolytical solutions containing hexamethylenetetramine and sodium fluoride were used. The morphology and chemical composition of formed coatings were examined by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). Also, salt spray test, hydrogen evolution and electrochemical tests (potentiodynamic polarization and electrochemical impedance spectroscopy) were conducted in order to study the corrosion behavior of the coated samples. It was found that the use of low frequency pulsed current for the PEO process reduces the film porosity and increases its thickness, compared with PEO films obtained by continuous anodization. The effect of the pulsed current signal was also analyzed for a two steps PEO process, observing changes in the morphological characteristics of the coatings which allow a better corrosion according electrochemical tests (short term corrosion measurements). However, long term tests results as hydrogen evolution and salt spray tests, indicated the opposite. Both the film porosity and thickness were affected by either the pulsing of the current or the use of a two-step process.

Idioma originalInglés
Número de artículo016539
PublicaciónMaterials Research Express
Volumen7
N.º1
DOI
EstadoPublicada - 1 ene 2020

Huella dactilar

Plasmas
Coatings
Oxidation
Hydrogen
Salts
Porosity
Methenamine
Corrosion
Sodium Fluoride
Electrochemical corrosion
Potentiodynamic polarization
Magnesium alloys
Electrochemical impedance spectroscopy
Oxides
Fourier transform infrared spectroscopy
Energy dispersive spectroscopy
Sodium
X ray diffraction
Scanning electron microscopy
Chemical analysis

Citar esto

Toro, L. ; Zuleta, A. A. ; Correa, E. ; Calderón, D. ; Galindez, Y. ; Calderón, J. ; Chacón, P. ; Valencia-Escobar, A. ; Echeverría E, F. / New insights on the influence of low frequency pulsed current on the characteristics of PEO coatings formed on AZ31B. En: Materials Research Express. 2020 ; Vol. 7, N.º 1.
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abstract = "In this work, anodic oxide layers on the surface of an AZ31 magnesium alloy were obtained by plasma electrolytic oxidation (PEO) process under low frequency pulsed current. For this, electrolytical solutions containing hexamethylenetetramine and sodium fluoride were used. The morphology and chemical composition of formed coatings were examined by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). Also, salt spray test, hydrogen evolution and electrochemical tests (potentiodynamic polarization and electrochemical impedance spectroscopy) were conducted in order to study the corrosion behavior of the coated samples. It was found that the use of low frequency pulsed current for the PEO process reduces the film porosity and increases its thickness, compared with PEO films obtained by continuous anodization. The effect of the pulsed current signal was also analyzed for a two steps PEO process, observing changes in the morphological characteristics of the coatings which allow a better corrosion according electrochemical tests (short term corrosion measurements). However, long term tests results as hydrogen evolution and salt spray tests, indicated the opposite. Both the film porosity and thickness were affected by either the pulsing of the current or the use of a two-step process.",
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Toro, L, Zuleta, AA, Correa, E, Calderón, D, Galindez, Y, Calderón, J, Chacón, P, Valencia-Escobar, A & Echeverría E, F 2020, 'New insights on the influence of low frequency pulsed current on the characteristics of PEO coatings formed on AZ31B', Materials Research Express, vol. 7, n.º 1, 016539. https://doi.org/10.1088/2053-1591/ab61ac

New insights on the influence of low frequency pulsed current on the characteristics of PEO coatings formed on AZ31B. / Toro, L.; Zuleta, A. A.; Correa, E.; Calderón, D.; Galindez, Y.; Calderón, J.; Chacón, P.; Valencia-Escobar, A.; Echeverría E, F.

En: Materials Research Express, Vol. 7, N.º 1, 016539, 01.01.2020.

Resultado de la investigación: Contribución a una revistaArtículo

TY - JOUR

T1 - New insights on the influence of low frequency pulsed current on the characteristics of PEO coatings formed on AZ31B

AU - Toro, L.

AU - Zuleta, A. A.

AU - Correa, E.

AU - Calderón, D.

AU - Galindez, Y.

AU - Calderón, J.

AU - Chacón, P.

AU - Valencia-Escobar, A.

AU - Echeverría E, F.

PY - 2020/1/1

Y1 - 2020/1/1

N2 - In this work, anodic oxide layers on the surface of an AZ31 magnesium alloy were obtained by plasma electrolytic oxidation (PEO) process under low frequency pulsed current. For this, electrolytical solutions containing hexamethylenetetramine and sodium fluoride were used. The morphology and chemical composition of formed coatings were examined by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). Also, salt spray test, hydrogen evolution and electrochemical tests (potentiodynamic polarization and electrochemical impedance spectroscopy) were conducted in order to study the corrosion behavior of the coated samples. It was found that the use of low frequency pulsed current for the PEO process reduces the film porosity and increases its thickness, compared with PEO films obtained by continuous anodization. The effect of the pulsed current signal was also analyzed for a two steps PEO process, observing changes in the morphological characteristics of the coatings which allow a better corrosion according electrochemical tests (short term corrosion measurements). However, long term tests results as hydrogen evolution and salt spray tests, indicated the opposite. Both the film porosity and thickness were affected by either the pulsing of the current or the use of a two-step process.

AB - In this work, anodic oxide layers on the surface of an AZ31 magnesium alloy were obtained by plasma electrolytic oxidation (PEO) process under low frequency pulsed current. For this, electrolytical solutions containing hexamethylenetetramine and sodium fluoride were used. The morphology and chemical composition of formed coatings were examined by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). Also, salt spray test, hydrogen evolution and electrochemical tests (potentiodynamic polarization and electrochemical impedance spectroscopy) were conducted in order to study the corrosion behavior of the coated samples. It was found that the use of low frequency pulsed current for the PEO process reduces the film porosity and increases its thickness, compared with PEO films obtained by continuous anodization. The effect of the pulsed current signal was also analyzed for a two steps PEO process, observing changes in the morphological characteristics of the coatings which allow a better corrosion according electrochemical tests (short term corrosion measurements). However, long term tests results as hydrogen evolution and salt spray tests, indicated the opposite. Both the film porosity and thickness were affected by either the pulsing of the current or the use of a two-step process.

KW - anodizing

KW - corrosion

KW - Mg-Al-Zn alloys

KW - plasma electrolytic oxidation

KW - salt fog test

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U2 - 10.1088/2053-1591/ab61ac

DO - 10.1088/2053-1591/ab61ac

M3 - Artículo

AN - SCOPUS:85078114537

VL - 7

JO - Materials Research Express

JF - Materials Research Express

SN - 2053-1591

IS - 1

M1 - 016539

ER -