PEO of pre-anodized Al-Si alloys: Corrosion properties and influence of sealings

M. Mohedano; E. Matykina; R. Arrabal; B. Mingo; A. Pardo

doi:10.1016/j.apsusc.2015.03.206

PEO of pre-anodized Al-Si alloys: Corrosion properties and influence of sealings

M. Mohedano, E. Matykina, R. Arrabal, B. Mingo, A. Pardo

Research output: Contribution to journal › Article › peer-review

Abstract

Voltage-controlled PEO coatings were developed on A356 aluminum alloys (gravity-cast and rheocast) with a pre-anodized layer. The influence of the alloy manufacturing process and the effect of Si-rich phase on the structure and composition of the oxide layers were evaluated using SEM, EDS and XRD. The pre-anodized oxide layer preserves the microstructure of the substrate due to the presence of secondary phases that have a different behavior relative to the matrix during anodizing. PEO coatings consisted of a mixture of α-Al₂O₃, γ-Al₂O₃ and mullite. The corrosion behavior and the effectiveness of different sealing techniques based on salts of nickel, cobalt, cerium and phosphonic acid were also studied. Post-treatments improved the hydrophobic properties of the coatings and showed a beneficial effect, significantly increasing the coating impedance and thereby reducing the susceptibility to corrosion.

Original language	English
Pages (from-to)	57-67
Number of pages	11
Journal	Applied Surface Science
Volume	346
DOIs	https://doi.org/10.1016/j.apsusc.2015.03.206
Publication status	Published - 1 Jan 2015

Keywords

Aluminum
Anodizing
Corrosion
PEO
Post-treatment

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10.1016/j.apsusc.2015.03.206

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title = "PEO of pre-anodized Al-Si alloys: Corrosion properties and influence of sealings",

abstract = "Voltage-controlled PEO coatings were developed on A356 aluminum alloys (gravity-cast and rheocast) with a pre-anodized layer. The influence of the alloy manufacturing process and the effect of Si-rich phase on the structure and composition of the oxide layers were evaluated using SEM, EDS and XRD. The pre-anodized oxide layer preserves the microstructure of the substrate due to the presence of secondary phases that have a different behavior relative to the matrix during anodizing. PEO coatings consisted of a mixture of α-Al2O3, γ-Al2O3 and mullite. The corrosion behavior and the effectiveness of different sealing techniques based on salts of nickel, cobalt, cerium and phosphonic acid were also studied. Post-treatments improved the hydrophobic properties of the coatings and showed a beneficial effect, significantly increasing the coating impedance and thereby reducing the susceptibility to corrosion.",

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T1 - PEO of pre-anodized Al-Si alloys

T2 - Corrosion properties and influence of sealings

AU - Mohedano, M.

AU - Matykina, E.

AU - Arrabal, R.

AU - Mingo, B.

AU - Pardo, A.

PY - 2015/1/1

Y1 - 2015/1/1

N2 - Voltage-controlled PEO coatings were developed on A356 aluminum alloys (gravity-cast and rheocast) with a pre-anodized layer. The influence of the alloy manufacturing process and the effect of Si-rich phase on the structure and composition of the oxide layers were evaluated using SEM, EDS and XRD. The pre-anodized oxide layer preserves the microstructure of the substrate due to the presence of secondary phases that have a different behavior relative to the matrix during anodizing. PEO coatings consisted of a mixture of α-Al2O3, γ-Al2O3 and mullite. The corrosion behavior and the effectiveness of different sealing techniques based on salts of nickel, cobalt, cerium and phosphonic acid were also studied. Post-treatments improved the hydrophobic properties of the coatings and showed a beneficial effect, significantly increasing the coating impedance and thereby reducing the susceptibility to corrosion.

AB - Voltage-controlled PEO coatings were developed on A356 aluminum alloys (gravity-cast and rheocast) with a pre-anodized layer. The influence of the alloy manufacturing process and the effect of Si-rich phase on the structure and composition of the oxide layers were evaluated using SEM, EDS and XRD. The pre-anodized oxide layer preserves the microstructure of the substrate due to the presence of secondary phases that have a different behavior relative to the matrix during anodizing. PEO coatings consisted of a mixture of α-Al2O3, γ-Al2O3 and mullite. The corrosion behavior and the effectiveness of different sealing techniques based on salts of nickel, cobalt, cerium and phosphonic acid were also studied. Post-treatments improved the hydrophobic properties of the coatings and showed a beneficial effect, significantly increasing the coating impedance and thereby reducing the susceptibility to corrosion.

KW - Aluminum

KW - Anodizing

KW - Corrosion

KW - PEO

KW - Post-treatment

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EP - 67

JO - Applied Surface Science

JF - Applied Surface Science

SN - 0169-4332

ER -

PEO of pre-anodized Al-Si alloys: Corrosion properties and influence of sealings

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Keywords

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