Effects of Voltage on Microstructure and Corrosion Resistance of Micro-arc Oxidation Ceramic Coatings Formed on KBM10 Magnesium Alloy

2017 ◽  
Vol 27 (1) ◽  
pp. 147-154 ◽  
Author(s):  
J. P. Lu ◽  
G. P. Cao ◽  
G. F. Quan ◽  
C. Wang ◽  
J. J. Zhuang ◽  
...  
2012 ◽  
Vol 571 ◽  
pp. 38-42
Author(s):  
Shun Qi Zheng ◽  
Li Ping Zhu ◽  
Gui Ru Chang ◽  
Chuang Lu ◽  
Xiao Jing Li

Micro-arc oxidation (MAO) method was used for the surface modification of MB3 magnesium alloy. The morphology feature, phase composition, and chemical composition of the formed ceramic coatings were studied by metallographic microscope, scanning electron microscopy (SEM), XRD, respectively. Drop test has been applied to study the corrosion resistance of MB3 Mg alloy with and without micro-arc oxidation treatment. The present result indicates that, through MAO, ceramic coatings were in-situ fabricated on the surface of MB3 Mg alloy, the micro-arc oxidation coating is relatively dense and uniform, maximum thickness is more than 97μm. The dominant phase of the coating is spinal Mg2SiO4 (Forsterite) and dissociative MgO (Periclase). Drop test shows that after oxidation the corrosion resistance of MB3 Mg alloy is greatly improved.


2011 ◽  
Vol 189-193 ◽  
pp. 1248-1252 ◽  
Author(s):  
Rui Ling Jia ◽  
Hong Ping Duan ◽  
Feng Guo ◽  
Xi Wei Zhai ◽  
Ya Hong Liang

Aluminium plate was cladded to magnesium alloy plate by using the explosive welding. The bonding morphology and composition of the explosive cladding plate was inspected by SEM and EDS. There is a wave bonding at the interface between aluminum plate and magnesium alloy plate. Then ceramic coatings were directly prepared on the surface of aluminum and magnesium alloy by micro-arc oxidation (MAO) in the same solution and at the same time. The microstructure and composition of MAO coatings were studies by SEM and EDS. The corrosion and wear resistance of MAO coatings on the two sides of the clad plate were investigated by salt spray tests and friction-wear test. The results show that the MAO coating on the Al surface consists of Al, O and Si elements, while MAO coating on the Mg surface consists of Mg, O and Si elements. The corrosion resistance of MAO coating on the Al surface was better than that on Mg surface of the explosive clad plate. The MAO coatings both on the Al surface and on the Mg surface can obviously improve the wear resistance of substrate.


2011 ◽  
Vol 299-300 ◽  
pp. 663-666 ◽  
Author(s):  
Ping Shi ◽  
Xue Dong Han

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.


Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 784
Author(s):  
Longlong Zhang ◽  
Yuanzhi Wu ◽  
Tian Zeng ◽  
Yu Wei ◽  
Guorui Zhang ◽  
...  

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.


2010 ◽  
Vol 146-147 ◽  
pp. 941-947
Author(s):  
Xi Chang Shi ◽  
Xiang Xiao ◽  
Bai Zhen Chen ◽  
Wei Shang

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.


2014 ◽  
Vol 960-961 ◽  
pp. 143-147
Author(s):  
Jun Zhao ◽  
Jian Jun Xi ◽  
Zhi Gang Wang ◽  
Chun Ping Zhao

Ceramic coatings were prepared on ZM5 magnetism substrate by micro-arc oxidation method with and without magnetism filed in silicate electrolyte. The morphology of the MAO coatings was investigated by scanning electron microscope (SEM). The friction coefficient of the MAO coatings prepared with magnetism is about 0.2 and more stable than the coatings prepared without magnetism. The polarization test indicated that the coating prepared with magnetism has better corrosion resistance.


2010 ◽  
Vol 105-106 ◽  
pp. 505-508 ◽  
Author(s):  
Zhen Dong Wu ◽  
Zhong Wen Yao ◽  
Fang Zhou Jia ◽  
Zhao Hua Jiang

The coatings containing zirconia were produced on LY12 Aluminium alloy by micro-arc oxidation in K2ZrF6 and NaH2PO2 solution. The composition, structure, hardness, friction and wear resistance and corrosion resistance of the coating were studied by XRD, SEM, EDS, ball-on-disk friction tester and electrochemical analyzer, respectively. The results show that coating was composed of m-ZrO2 and t-ZrO2. There were a large amount of Zr and O and a little Al, P and K in the coating. The thickness of coating prepared for 3h was 168μm and the maximum value of the hardness was up to 16.75GPa. The friction and wear resistance and corrosion resistance were improved, compared with the LY12 aluminium alloy substrate.


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