Improvement in corrosion resistance of micro arc oxidation coating formed on AZ91D magnesium alloy via applying a nano-crystalline sol–gel layer

2011 ◽  
Vol 59 (2) ◽  
pp. 297-303 ◽  
Author(s):  
M. Laleh ◽  
Farzad Kargar ◽  
A. Sabour Rouhaghdam
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Sol Gel ◽  
Az91d Magnesium Alloy ◽  
Gel Layer ◽  
Nano Crystalline ◽  
Micro Arc Oxidation

scholarly journals Preparation and Characterization of a Sol–Gel AHEC Pore-Sealing Film Prepared on Micro Arc Oxidized AZ31 Magnesium Alloy

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 784
Author(s):  
Longlong Zhang ◽  
Yuanzhi Wu ◽  
Tian Zeng ◽  
Yu Wei ◽  
Guorui Zhang ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Sol Gel ◽  
Oxide Coating ◽  
Az31 Magnesium Alloy ◽  
Hydroxyethyl Cellulose ◽  
Gel Spinning ◽  
Test Analysis ◽  
Pore Sealing ◽  
Micro Arc Oxidation

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.

PREPARATION OF COMPOSITE COATING ON AZ91D MAGNESIUM ALLOY BY SILICA SOL-MICRO-ARC OXIDATION

2016 ◽  
Vol 23 (04) ◽  
pp. 1650029 ◽  
Author(s):  
ZHONGCAI SHAO ◽  
FEIFEI ZHANG ◽  
RUIQIANG ZHAO ◽  
XIAOYI SHEN
Keyword(s):  
Magnesium Alloy ◽  
Composite Coating ◽  
Sol Gel ◽  
Silica Sol ◽  
Test Results ◽  
X Ray Diffraction ◽  
Az91d Magnesium Alloy ◽  
Electrochemical Testing ◽  
Sol Gel Process ◽  
Micro Arc Oxidation

Composite coating was prepared on AZ91D magnesium alloy with a new method which combined silica sol with micro-arc oxidation (MAO). The MAO coating was prepared on the basis of MAO solution, and then coated by sol–gel process. The composite coating was obtained after second MAO treatment. Scanning electron microscopy coupled with X-ray diffraction (XRD), energy spectrum analysis and electrochemical testing was applied to characterize the properties of MAO coating and composite coating. The experimental test results indicated that the Si element derived from SiO2 gel particle embedded into the MAO coating by second MAO treatment. The surface of composite coating became dense and the holes were smaller with silica sol sealing process. The corrosion resistance of composite coating was improved than the MAO coating.

Corrosion Behavior of the Composite Coatings Prepared on Magnesium Alloy AZ91 in Na2SO4 Solution

2014 ◽  
Vol 900 ◽  
pp. 522-525
Author(s):  
Wei Shang ◽  
Zhou Lan Yin ◽  
Yu Qing Wen ◽  
Xu Feng Wang
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Composite Coatings ◽  
Sol Gel ◽  
Alloy Az91 ◽  
Magnesium Alloy Az91 ◽  
Micro Arc Oxidation ◽  
Gel Technique

The composite coatings were obtained on a magnesium alloy by micro-arc oxidation (MAO) and sol-gel technique. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) were used to evaluate the corrosion behavior of MAO coating and composite coatings in a 3.5% Na2SO4 solution. The results show that corrosion behavior of the MAO coating and composite coatings are different at different immersion times. The corrosion resistance of composite coatings is good than that of MAO coating.

The Characteristic of the Coating Prepared on Magnesium Alloy AZ91D by Micro-Arc Oxidization

2011 ◽  
Vol 418-420 ◽  
pp. 751-755
Author(s):  
Wei Shang ◽  
Yu Qing Wen ◽  
Yan Yun Qin ◽  
Fang He ◽  
Ji Yun Fang
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Corrosion Protection ◽  
Electrolyte Solution ◽  
Phase Component ◽  
Az91d Magnesium Alloy ◽  
Acacia Gum ◽  
Alloy Az91d ◽  
Micro Arc Oxidation ◽  
Electric Parameters

Micro-arc oxidation coating on AZ91D magnesium alloy is prepared in a NaAlO2-NaOH-montmorillonite-acacia gum electrolyte solution with adaptive electric parameters. The morphologies, composition, phase component of the coatings are analyzed by SEM, EDS and XRD. And CHI600B electrochemistry workstation is employed to investigate the corrosion resistance of the coatings. The results show that the MAO coating has the relatively uniform in thickness. The coating is mainly composed of MgO and MgAl2O4 phases. It provides corrosion protection by acting as a barrier. The MAO coating enhances the corrosion resistance of the magnesium alloy AZ91D to some extent.

A Preliminary Study of Anodization and Electroless Ni–P Plating on AZ80 Magnesium Alloy

2011 ◽  
Vol 299-300 ◽  
pp. 663-666 ◽  
Author(s):  
Ping Shi ◽  
Xue Dong Han
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Weight Ratio ◽  
High Strength ◽  
Surface Modifications ◽  
Atomic Ratio ◽  
Az80 Magnesium Alloy ◽  
Micro Arc Oxidation ◽  
Preliminary Study ◽  
Electroless Ni

Magnesium alloys are being used as structural components in industry because of their high strength to weight ratio. But their high electrochemical activity and poor corrosion resistance limited their applications. Therefore, surface modifications are needed for protection purpose. This paper studied the anodic micro-arc oxidation and electroless Ni-P plating surface modifications on AZ80 magnesium alloy. The SEM, XRD and EDS were used to characterize the surface coating. It shows that a micro-porous MgO layer with the pores size 5 – 20 μm was fabricated on the bare magnesium alloy. The nodule Ni-P deposition could be prepared on the out layer of MgO with Ni/P atomic ratio being 1.4. The pores in MgO layer could be sealed by the following Ni-P deposition. Therefore the corrosion resistance of the magnesium alloy could be further improved.

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