Study on micro-arc oxidation coating of magnetic metal powder composite magnesium alloy

Purpose The purpose of this paper is to prepare composite micro-arc oxide coatings with better wear resistance and corrosion resistance. Design/methodology/approach A nickel powder composite micro-arc oxide film was prepared on the surface of the magnesium alloy by the method of organically combining ultra-fine Ni powder with micro arc oxidation film layer. In this experiment, the changes in the corrosion resistance and microstructure of the composite film layer after adding Ni powder were studied, and the effect of the addition of glycerin on the corrosion resistance of the film layer was analyzed. Findings The results show that the ultra-fine nickel powder was successfully prepared by the liquid phase reduction method, and the micro-arc oxidation process was modified under the optimal addition amount. The surface of the micro-arc oxide film made of ultra-fine nickel powder was found by SEM to have smooth surfaces and few holes. According to X-ray diffraction analysis, the phase composition of the micro-arc oxide film layer was Mg, Ni, NiSiO4, MgNi (SiO4) and Mg2SiO4. According to the results of electrochemical tests, the corrosion resistance of the micro-arc oxidation composite film layer was improved after the addition of ultra-fine Ni powder, the corrosion current was greatly reduced and the impedance has been improved. And after adding glycerin, the surface of the film layer becomes denser, and the corrosion resistance of the micro-arc oxide film is significantly improved. Originality/value Through this experimental research, a micro-arc oxide coating of powder composite magnesium alloy was successfully prepared. The corrosion resistance of the micro-arc oxidation film layer has been improved, and certain functions had been given to the micro-arc oxidation composite film, which has increased the application field of magnesium alloys.

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Study on Micro-Arc Oxidation Behavior of AZ91 Magnesium Alloy in Aluminate Environmentally Friendly Electrolyte

Materials Science Forum ◽

10.4028/www.scientific.net/msf.1003.67 ◽

2020 ◽

Vol 1003 ◽

pp. 67-75

Author(s):

Xian Ming Chen ◽

Ying Ying Fan

Keyword(s):

Corrosion Resistance ◽

Electron Microscope ◽

Magnesium Alloy ◽

Oxide Film ◽

Oxidation Behavior ◽

Salt Spray ◽

Alkaline Electrolyte ◽

Az91 Magnesium Alloy ◽

Micro Arc Oxidation ◽

Az91 Magnesium

In aluminate alkaline electrolyte the effect of aluminate on the microstructure and properties and the MAO(micro-arc oxidation) behavior of micro-arc oxide film of AZ91 magnesium alloy was studied. Transmission electron microscope(TEM), energy dispersive spectrum (EDS), X-ray diffraction(XRD), salt spray test and scanning electron microscope(SEM)were used to analyze and characterize the structure and properties of the film. The results show that the concentration of aluminate has an important effect on the tank voltage, corrosion resistance, surface morphology and phase structure of micro-arc oxidation film. The corrosion resistance and film quality of the film were increased first and then decreased, but the surface roughness decreased first and then increased with the increase of aluminate concentration from 5g/L to 30g/L. At our work, the concentration of 10g/L aluminate electrolyte is most favorable to the formation of micro-arc oxide film.

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PREPARATION OF GRAYISH BLACK FILM ON AM50 MAGNESIUM ALLOY BY CHEMICAL CONVERSION–MICRO-ARC OXIDATION

Surface Review and Letters ◽

10.1142/s0218625x17500123 ◽

2016 ◽

Vol 24 (01) ◽

pp. 1750012 ◽

Cited By ~ 1

Author(s):

ZHONGCAI SHAO ◽

FEIFEI ZHANG ◽

QINGFANG ZHANG ◽

LI YANG ◽

XIAOYI SHEN

Keyword(s):

Corrosion Resistance ◽

Magnesium Alloy ◽

Composite Film ◽

Chemical Conversion ◽

X Ray Diffraction ◽

Black Film ◽

X Ray ◽

Electrochemical Tests ◽

Micro Arc Oxidation ◽

Optimum Formula

The grayish black film was prepared on AM50 magnesium alloy with a new method which combined chemical conversion with micro-arc oxidation (MAO). The optimum formula of chemical conversion was obtained by L9(34) orthogonal test. Meanwhile, the morphology, structure, composition and corrosion resistance of films were analyzed by scanning electron microscopy (SEM), energy spectrum analysis (energy dispersive X-ray spectroscopy (EDS)), X-ray diffraction (XRD), electrochemical tests and CuSO4 drip experiment. The results indicated that Mo element was introduced into the MAO film by chemical conversion pretreatment. The surface of composite film was smooth and compact. The main phase composition of the composite film were SiO2, Mo9O[Formula: see text], MgSiO[Formula: see text] Mg2SiO4 and Mo9O[Formula: see text] was identified to be responsible for giving color to the film. The corrosion resistance of the grayish black film was improved obviously.

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Preparation and Characterisation of CaP-Containing Coating on Magnesium Alloy by Micro-Arc Oxidation and Hydrothermal Treatment

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.496.383 ◽

2012 ◽

Vol 496 ◽

pp. 383-386

Author(s):

Li Min Chang ◽

Dan Dan Xu ◽

Wei Liu

Keyword(s):

Corrosion Resistance ◽

Magnesium Alloy ◽

Oxide Film ◽

Hydrothermal Treatment ◽

Electrochemical Methods ◽

Dicalcium Phosphate ◽

Dicalcium Phosphate Dihydrate ◽

Phosphate Dihydrate ◽

Micro Arc Oxidation ◽

Hank’S Solution

Micro-arc oxidation (MAO) together with hydrothermal treatment had been performed to improve the corrosion resistance of magnesium alloy. The oxide films were hydrothermally heated at 150°C for 2h. The morphology of samples were characterized by SEM/EDS. The phase compositions were examined by TF-XRD. The corrosion resistance of the coatings was evaluated by electrochemical methods in Hank’s solution. The MAO films displayed porous and rough structure and were mainly composed of MgO and MgAl2O4. After hydrothermal treatment, a dicalcium phosphate dihydrate (DCPD) coating formed on the oxide film. The corrosion resistance of the MAO film and DCPD coating was increased by about 12 and 40 times higher than that of bare magnesium alloy.

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Corrosion resistance of composite oxide film prepared on Ca-added flame-resistant magnesium alloy AZCa612 by micro-arc oxidation

Corrosion Science ◽

10.1016/j.corsci.2017.06.008 ◽

2017 ◽

Vol 125 ◽

pp. 99-105 ◽

Cited By ~ 11

Author(s):

Oi Lun Li ◽

Mika Tsunakawa ◽

Yuta Shimada ◽

Kae Nakamura ◽

Kazuhito Nishinaka ◽

...

Keyword(s):

Corrosion Resistance ◽

Magnesium Alloy ◽

Oxide Film ◽

Composite Oxide ◽

Micro Arc Oxidation

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

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.299-300.663 ◽

2011 ◽

Vol 299-300 ◽

pp. 663-666 ◽

Cited By ~ 1

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

Metals ◽

10.3390/met11050784 ◽

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.

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Lithium-Incorporated Nanoporous Coating Formed by Micro Arc Oxidation (MAO) on Magnesium Alloy with Improved Corrosion Resistance, Angiogenesis and Osseointegration

Journal of Biomedical Nanotechnology ◽

10.1166/jbn.2019.2767 ◽

2019 ◽

Vol 15 (6) ◽

pp. 1172-1184 ◽

Cited By ~ 1

Author(s):

Wei Liu ◽

Tingting Li ◽

Chao Yang ◽

Dong Wang ◽

Guo He ◽

...

Keyword(s):

Corrosion Resistance ◽

Magnesium Alloy ◽

Micro Arc Oxidation

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Corrosion Resistance by Sodium Metavanadate for AZ91D Magnesium Alloy

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.575.170 ◽

2014 ◽

Vol 575 ◽

pp. 170-174 ◽

Cited By ~ 1

Author(s):

Toha Nor Fadzilah ◽

S. Norbahiyah ◽

Mohd Zain Mohamad Zamzuri

Keyword(s):

Corrosion Resistance ◽

Magnesium Alloy ◽

Oxide Film ◽

Corrosion Test ◽

Energy Dispersive Spectrometry ◽

Optical Microscope ◽

X Ray ◽

Sodium Metavanadate ◽

Az91d Magnesium Alloy ◽

Polarization Technique

An oxide film was prepared on AZ91D magnesium alloy by anodizing in solution containing sodium metavanadate (NaVO3). The corrosion resistance of the substrate was investigated at a fixed current density 10 mA/cm2for 5 mins with different concentration of solution in the range of 0 – 1.0 g/l. The surface morphology, phase structure and corrosion resistance of oxide film were studied by optical microscope, scanning electron microscope (SEM) and energy dispersive spectrometry (EDS) and X-ray diffractometer (XRD), potentiodynamic polarization technique and corrosion test.

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