scholarly journals The effect of pulse frequency on the electrochemical properties of micro arc oxidation coatings formed on magnesium alloy

2013 ◽  
Vol 1 (4) ◽  
pp. 318-322 ◽  
Author(s):  
Xianghua Song ◽  
Jianhong Lu ◽  
Xijiang Yin ◽  
Jianping Jiang ◽  
Jing Wang
Keyword(s):  
Magnesium Alloy ◽  
Electrochemical Properties ◽  
Pulse Frequency ◽  
Micro Arc Oxidation

Calcium and Phosphate Biocoatings on Magnesium Alloy Fabricated by Micro-Arc Oxidation

2010 ◽  
Vol 105-106 ◽  
pp. 565-568 ◽  
Author(s):  
Chen Ma ◽  
Xiang Yu Zhang ◽  
Li Jie Qu ◽  
Mu Qin Li
Keyword(s):  
Magnesium Alloy ◽  
Friction Coefficient ◽  
Composite Coatings ◽  
Pulse Frequency ◽  
Test Machine ◽  
Anode Polarization ◽  
Corrosion Resistant ◽  
Alloy Substrate ◽  
Phosphate Ions ◽  
Micro Arc Oxidation

Calcium phosphate biocoatings were fabricated on the surface of magnesium alloy by micro-arc oxidation (MAO) technique. The properties of biocoatings related with MAO technics parameters and the electrolyte constitute. The surface morphology, constitute and friction coefficient were studied by SEM XRD and fret test machine. The results indicated that the optimum electrolyte was CaCO3-Na3PO4 contained 20g/L phosphate ions and 1.5 Ca/P ratio, and the optimum technics parameters was 350V oxidation voltage for10min, 500HZ pulse frequency and 1:10 in duty cycle. The main phase constitutes of the porous biocoatings contained were Mg, MgO, Mg3(PO4)2 and CaNaPO4. The anode polarization potential of the coating was -1.36V and enhanced about 0.29V compared with that of magnesium alloy substrate, which indicated that the biocoatings had better corrosion resistant properties. The friction coefficient of the biocoatings was 0.23 and decreased 0.15 compared with that of magnesium alloy substrate, which indicated that the biocoatings had better wear resistant properties. The biocoatings could induce hydroxyapatite to form on its surface after soaked in body fluid, which showed that the composite coatings owned good bioactivity.

Na2CO3-induced Gas Evolution Reaction and Morphology Modulation on Magnesium Alloy during Micro-arc Oxidation

2011 ◽  
Vol 26 (7) ◽  
pp. 721-725
Author(s):  
Xiao-Bo WANG ◽  
Xiu-Bo TIAN ◽  
Chun-Zhi GONG ◽  
Shi-Qin YANG
Keyword(s):  
Magnesium Alloy ◽  
Gas Evolution ◽  
Micro Arc Oxidation

INVESTIGATION OF PULSE FREQUENCY ON FUSION ZONE CHARACTERISTICS OF GTA WELDED AZ31B MAGNESIUM ALLOY JOINTS

2020 ◽  
Vol 15 (2) ◽  
Author(s):  
Subravel V
Keyword(s):  
Magnesium Alloy ◽  
Tensile Properties ◽  
Fusion Zone ◽  
Welding Speed ◽  
Pulse Frequency ◽  
Pulsed Current ◽  
Az31b Magnesium Alloy ◽  
Gas Tungsten Arc ◽  
Gas Tungsten ◽  
Different Levels

In this investigation an attempt has been made to study the effect of welding on fusion characteristics of pulsed current gas tungsten arc welded AZ31B magnesium alloy joints. Five joints were fabricated using different levels of welding speed (105 mm/min –145 mm/min). From this investigation, it is found that the joints fabricated using a welding speed of 135 mm/min yielded superior tensile properties compared to other joints. The formation of finer grains and higher hardness in fusion zone and uniformly distributed precipitates are the main reasons for the higher tensile properties of these joints

scholarly journals Biocoatings synthesized on magnesium alloy in system Ca3(PO4)2–CaSiO3 by micro-arc oxidation method

2021 ◽  
Vol 1954 (1) ◽  
pp. 012037
Author(s):  
M B Sedelnikova ◽  
A V Ugodchikova ◽  
T V Tolkacheva ◽  
Yu P Sharkeev ◽  
O V Kazmina ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Oxidation Method ◽  
Micro Arc Oxidation

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.

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.

Local corrosion behavior and model of micro-arc oxidation HA coating on AZ31 magnesium alloy

2017 ◽  
Vol 331 ◽  
pp. 179-188 ◽  
Author(s):  
Huijuan Ma ◽  
Yanhong Gu ◽  
Shujing Liu ◽  
Juntie Che ◽  
Dawei Yang
Keyword(s):  
Magnesium Alloy ◽  
Corrosion Behavior ◽  
Local Corrosion ◽  
Az31 Magnesium Alloy ◽  
Ha Coating ◽  
Micro Arc Oxidation

The Characteristic of Ceramic Coatings Prepared on Magnesium Alloy AZ91D by Micro-Arc Oxidization in Silicate Electrolyte

2010 ◽  
Vol 146-147 ◽  
pp. 941-947
Author(s):  
Xi Chang Shi ◽  
Xiang Xiao ◽  
Bai Zhen Chen ◽  
Wei Shang
Keyword(s):  
Magnesium Alloy ◽  
Outer Region ◽  
Ceramic Coatings ◽  
Nacl Solution ◽  
Acacia Gum ◽  
Alloy Az91d ◽  
Micro Arc Oxidation ◽  
Distribution Phase ◽  
Magnesium Surface ◽  
Better Than

A novel process of micro-arc oxidation (MAO) on AZ91D magnesium alloy is investigated in a Na2SiO3-NaOH-montmorillonite-EDTA-acacia gum electrolyte solution. The morphologies, elements distribution, phase components of the coatings are characterized by SEM, EDS and XRD. And CHI600 electrochemistry corrosion workstation is employed to investigate the property of corrosion resistance of the coatings. Furthermore, the anti-corrosion behavior is analyzed immersed in 3.5 wt. % NaCl solution. The results reveal that the ceramic coatings have the relatively dense and uniform in thickness and the silicon element tends to present primarily in the outer region of the coatings. The XRD results indicate that the oxide films are mainly composed of Mg2SiO4 and MgAl2O4 phases. The immersion results show that the corrosion resistances of the ceramic coatings on AZ91D magnesium surface are better than the magnesium substrate.

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