Improved corrosion resistance of Al2O3 ceramic coatings on AZ31 magnesium alloy fabricated through cathode plasma electrolytic deposition combined with surface pore-sealing treatment

The purpose of this study was to improve the cellular compatibility and corrosion resistance of AZ31 magnesium alloy and to prepare a biodegradable medical material. An aminated hydroxyethyl cellulose (AHEC) coating was successfully prepared on the surface of a micro-arc oxide +AZ31 magnesium alloy by sol–gel spinning. The pores of the micro-arc oxide coating were sealed. A polarization potential test analysis showed that compared to the single micro-arc oxidation coating, the coating after sealing with AHEC significantly improved the corrosion resistance of the AZ31 magnesium alloy and reduced its degradation rate in simulated body fluid (SBF). The CCK-8 method and cell morphology experiments showed that the AHEC + MAO coating prepared on the AZ31 magnesium alloy had good cytocompatibility and bioactivity.

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Effect of Duty Cycle on Properties of Al2O3 Ceramic Coatings Fabricated on TiAl Alloy via Cathodic Plasma Electrolytic Deposition

Materials ◽

10.3390/ma11101962 ◽

2018 ◽

Vol 11 (10) ◽

pp. 1962 ◽

Cited By ~ 1

Author(s):

Shaoqing Wang ◽

Faqin Xie ◽

Xiangqing Wu ◽

Jixiang An

Keyword(s):

Electron Microscopy ◽

Wear Resistance ◽

Heat Resistance ◽

Duty Cycle ◽

Tial Alloy ◽

Ceramic Coatings ◽

Electrolytic Deposition ◽

Al2o3 Ceramic ◽

Cathodic Plasma ◽

Plasma Electrolytic

In order to study the effect of duty cycle during the cathodic plasma electrolytic deposition (CPED) process, Al2O3 ceramic coatings were fabricated via the CPED technique on prepared TiAl alloy in an Al(NO3)3 electrolyte with different duty cycles. Microstructure, morphology, and chemical compositions of coatings were analyzed by scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), transmission electron microscopy (TEM), and X-ray diffraction (XRD). The mechanical properties, such as thickness, hardness, and binding strength, were also characterized, and heat-resistance and wear-resistance tested. The results indicated that duty cycle mainly affected the relative crystallinity of CPED coatings. As the duty cycle increased, the crystallinity of CPED coatings increased, the content of Al(OH)3 and γ-Al2O3 decreased, and the content of α-Al2O3 increased. The thickness and bonding strength both increased firstly and then decreased, while hardness increased as duty cycle increased. Heat-resistance and wear-resistance of TiAl alloy with CPED coating was highly improved compared to that of TiAl alloy substrate without CPED coating.

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TiO2Deposition on AZ31 Magnesium Alloy Using Plasma Electrolytic Oxidation

Journal of Nanomaterials ◽

10.1155/2013/319437 ◽

2013 ◽

Vol 2013 ◽

pp. 1-8 ◽

Cited By ~ 21

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.

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Preparation and properties of ceramic coatings by cathode plasma electrolytic deposition on titanium alloy

Surface and Coatings Technology ◽

10.1016/j.surfcoat.2017.04.033 ◽

2017 ◽

Vol 325 ◽

pp. 708-714 ◽

Cited By ~ 7

Author(s):

Chenxu Liu ◽

Jin Zhang ◽

Shuguang Zhang ◽

Peng Wang ◽

Yong Lian ◽

...

Keyword(s):

Titanium Alloy ◽

Ceramic Coatings ◽

Electrolytic Deposition ◽

Cathode Plasma ◽

Plasma Electrolytic

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Corrosion Behaviour of Preserved PEO Coating on AZ31 Magnesium Alloy

Communications - Scientific letters of the University of Zilina ◽

10.26552/com.c.2021.2.b76-b88 ◽

2020 ◽

Vol 23 (2) ◽

pp. B76-B88

Author(s):

Filip Pastorek ◽

Milan Štrbák ◽

Daniel Kajánek ◽

Martina Jacková ◽

Jana Pastorková ◽

...

Keyword(s):

Corrosion Resistance ◽

Magnesium Alloy ◽

Treatment Process ◽

Corrosion Behaviour ◽

Salt Spray ◽

Az31 Magnesium Alloy ◽

Electrochemical Tests ◽

Marine Transport ◽

Electrolytic Oxidation ◽

Plasma Electrolytic

A surface treatment process, composed of plasma electrolytic oxidation (PEO) and sealing by temporary oil preservation system containing corrosion inhibitors, was performed on AZ31 magnesium alloy in order to improve its corrosion resistance in environments containing chlorides. Both atmospheric and immersion conditions were evaluated by electrochemical tests in 0.1M NaCl solution together with salt spray test according to STN EN ISO 9227 standard. The obtained results confirmed significant improvement of corrosion resistance reached by the PEO sealing in aggressive environments compared to the pure PEO coating on AZ31 surface. Hence, such a duplex coating is a very perspective alternative for magnesium alloy applications in severe conditions or for temporary protection of magnesium products coated by the PEO during marine transport.

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