Microstructure and Corrosion Resistance of Electrophoretic Deposited Carbonated Hydroxyapatite-Graphene Oxide Composite Coatings on AZ91 Magnesium Alloy

The microstructures and corrosion resistance of AZ91 and AZ91+0.5 wt.% erbium (Er) magnesium alloys were studied, respectively. The results show that the Er addition in scrap AZ91 magnesium alloy can improve the corrosion resistance, markedly. The discontinuous precipitation phase (DPP) for Mg17Al12was retarded and the amount of DPP was decreased by 41% due to the formation of Al8ErMn4phase during solidification. The amount of continuous precipitation phase (CPP) in grains was decreased by 8% because of the formation of Al7ErMn5phase during solidification.

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Corrosion and Protection of Magnesium Alloys

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1120-1121.1078 ◽

2015 ◽

Vol 1120-1121 ◽

pp. 1078-1082 ◽

Cited By ~ 2

Author(s):

Yang Yang Lv ◽

Ling Feng Zhang

Keyword(s):

Corrosion Resistance ◽

Magnesium Alloy ◽

Magnesium Alloys ◽

Automotive Industry ◽

Physical And Mechanical Properties ◽

Current Status ◽

Strain Rates ◽

Metallic Materials ◽

Az91 Magnesium Alloy ◽

Az91 Magnesium

Magnesium alloy as a green material in the 21st century, because of its excellent physical and mechanical properties of metallic materials as an ideal in the automotive industry, electronic industry and aviation, aerospace and other industries[1]. However, poor corrosion resistance of magnesium alloys become an important issue hinder application of magnesium alloys[2]. So magnesium alloy corrosion problems and the current status of research paper reviews several magnesium alloy protection methods at home and abroad, and also highlighted with our latest laser shock (LSP) study of AZ91 magnesium alloy at high strain rates of corrosion resistance results.

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Influence of Aliquat 336 on tribological properties of electroless ternary nanocomposite coatings on AZ91 alloy

Proceedings of the Institution of Mechanical Engineers Part E Journal of Process Mechanical Engineering ◽

10.1177/0954408917731937 ◽

2017 ◽

Vol 232 (5) ◽

pp. 613-621 ◽

Cited By ~ 1

Author(s):

Mohd Imran Ansari ◽

Dineshsingh G Thakur

Keyword(s):

Magnesium Alloy ◽

Cationic Surfactant ◽

Tribological Properties ◽

Surface Engineering ◽

Composite Coatings ◽

Nanocomposite Coatings ◽

Az91 Alloy ◽

Aliquat 336 ◽

Az91 Magnesium Alloy ◽

Az91 Magnesium

Incorporation of fine nanoparticles and cationic surfactant (Aliquat 336) within an ENi–P matrix has given a new dimension to the field of nanocomposite coatings. It describes the surface engineering processes currently used for the protection of AZ91 magnesium alloy surface against wear, including electroless nano-composite coatings. The present work aims to investigate the influence of Aliquat 336 cationic surfactant on the microhardness and tribological properties of electroless (Ni–P–ZnO) ternary alloy nanocomposite coatings on AZ91 magnesium alloy substrate from acidic bath. The results revealed that there was a significant improvement in the microhardness and wear resistance of the coated surface by the addition of cationic surfactant at a concentration of 1.5 g/L as compared to the coating obtained without the addition of cationic surfactant in the chemical bath. These results are thus clearly indicative of the fact that the component of life of members made from substrate subjected to nanocomposite coatings with varying the concentration of surfactant can be greatly improved, thereby preventing early or regular failures, and increasing service life.

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Ceria Coatings Prepared by Sol-Gel Approach on AZ91 Magnesium Alloy

Materials Science Forum ◽

10.4028/www.scientific.net/msf.898.1369 ◽

2017 ◽

Vol 898 ◽

pp. 1369-1380 ◽

Cited By ~ 1

Author(s):

Hui Min Han ◽

Dan Tong Wang ◽

Hua Qian Yu ◽

Min Zuo ◽

Li Hong Wang ◽

...

Keyword(s):

Heat Treatment ◽

Corrosion Resistance ◽

Magnesium Alloy ◽

Sol Gel ◽

Electrochemical Corrosion ◽

Chemical Conversion ◽

Corrosion Current ◽

Az91 Alloy ◽

Az91 Magnesium Alloy ◽

Az91 Magnesium

The ceria coatings on AZ91 substrates were successfully synthesized by chemical conversion and the corrosion resistance of AZ91 samples with and without ceria coatings were evaluated by means of electrochemical corrosion in 3.5 wt.% NaCl solution. According to the parameters derived from the polarization date, the Icorr (the corrosion current density) values of the coated samples are smaller than that of bare one, indicating that the corrosion resistance of AZ91 alloys has been improved to some extent. The influence of fluoridated pretreatment, inter-layer heat treatment, sintering temperature and the layer of films on the performance of ceria coatings were also investigated. It was found that the inter-layer heat treatment has no influence on improving the anticorrosion resistance of AZ91 alloy. In comparison with the bare one, the Icorr of optimal sample is about 0.0219mA/cm2, which decreases by two orders of magnitude, indicating that the ceria coatings could significantly improve the corrosion resistance of AZ91 magnesium alloy.

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Corrosion Resistance of RE-AZ91 Magnesium Alloys

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.933.66 ◽

2014 ◽

Vol 933 ◽

pp. 66-70

Author(s):

Jun Jie Yang ◽

Yao Li ◽

Ping Xue

Keyword(s):

Tensile Strength ◽

Corrosion Resistance ◽

Magnesium Alloy ◽

Mg Alloy ◽

Constant Voltage ◽

High Tensile Strength ◽

Az91 Magnesium Alloy ◽

Az91 Magnesium ◽

Good Heat Resistance ◽

Good Heat

Rare Earth (RE) were added to industrial AZ91 magnesium alloy, so that RE-AZ91 Mg alloy was produced by the process of die casting, so as to study the effect of RE on corrosion resistance and tensile strength of Mg alloy. The experiment results show that RE addition could improve the tensile strength and corrosion resistance of magnesium alloy at a certain amount of RE. RE-AZ91 had a good heat resistance, corrosion resistance at a high temperature or in the environment applied constant voltage, with a high tensile strength.

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Improvement of AZ91 Alloy Corrosion Properties by Duplex NI-P Coating Deposition

Materials ◽

10.3390/ma13061357 ◽

2020 ◽

Vol 13 (6) ◽

pp. 1357 ◽

Cited By ~ 1

Author(s):

Jaromír Wasserbauer ◽

Martin Buchtík ◽

Jakub Tkacz ◽

Stanislava Fintová ◽

Jozef Minda ◽

...

Keyword(s):

Corrosion Resistance ◽

Magnesium Alloy ◽

Corrosion Behavior ◽

Electrochemical Impedance ◽

Salt Spray ◽

Az91 Alloy ◽

Neutral Salt ◽

Az91 Magnesium Alloy ◽

Corrosion Properties ◽

Az91 Magnesium

The corrosion behavior of duplex Ni-P coatings deposited on AZ91 magnesium alloy was studied. The electroless deposition process of duplex Ni-P coating consisted in the preparation of low-phosphorus Ni-P coating (5.7 wt.% of P), which served as a bond coating and high-phosphorus Ni-P coating (11.5 wt.% of P) deposited on it. The duplex Ni-P coatings with the thickness of 25, 50, 75 and 100 µm were deposited on AZ91 magnesium alloy. The electrochemical corrosion behavior of coated AZ91 magnesium alloy was investigated by electrochemical impedance spectroscopy and potentiodynamic polarization method in 0.1 M NaCl. Obtained results showed a significant improvement in the corrosion resistance of coated specimens when compared to uncoated AZ91 magnesium alloy. From the results of the immersion tests in 3.5 wt.% NaCl, 10% solution of HCl and NaOH and 5% neutral salt spray, a noticeable increase in the corrosion resistance with the increasing thickness of the Ni-P coating was observed.

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Two-Step Anodization of AZ91 Magnesium Alloy

Materials Science Forum ◽

10.4028/www.scientific.net/msf.488-489.653 ◽

2005 ◽

Vol 488-489 ◽

pp. 653-656 ◽

Cited By ~ 3

Author(s):

Rong Fa Zhang ◽

Da Yong Shan ◽

En Hou Han

Keyword(s):

Corrosion Resistance ◽

Magnesium Alloy ◽

Salt Spray ◽

Az91 Magnesium Alloy ◽

Anodic Coating ◽

Excellent Corrosion Resistance ◽

Long Time ◽

Az91 Magnesium ◽

Short Time ◽

Salt Spray Testing

Among four AZ91 samples, two were once anodized and the others were twice anodized in two electrolytic baths. After twice anodization, two coatings coexist on the base metal. Surface morphology showed that for one of twice anodic coatings (sample 2), the second coating only existed on some places and sealed some pores of the first coating after short time on the second anodizing. However, for another twice anodic coating (namely sample 4), the second anodization spent very long time and the coating was thick and loose. Salt spray testing showed that sample 2 had the most excellent corrosion resistance and the reason is discussed.

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