Improved corrosion resistance of friction stir welded magnesium alloy with micro-arc oxidation/electroless plating duplex coating

2021 ◽  
Vol 257 ◽  
pp. 123753
Author(s):  
Jiaan Liu ◽  
Shihao Li ◽  
Zhiwu Han ◽  
Renzhong Cao
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Electroless Plating ◽  
Friction Stir ◽  
Duplex Coating ◽  
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.

EFFECT OF FRICTION STIR PROCESSING ON CORROSION BEHAVIOR OF CAST AZ91C MAGNESIUM ALLOY

2019 ◽  
Vol 26 (06) ◽  
pp. 1850213 ◽  
Author(s):  
BEHZAD HASSANI ◽  
RUDOLF VALLANT ◽  
FATHALLAH KARIMZADEH ◽  
MOHAMMAD HOSSEIN ENAYATI ◽  
SOHEIL SABOONI ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Corrosion Behavior ◽  
Friction Stir Processing ◽  
Potentiodynamic Polarization ◽  
Passive Layer ◽  
Friction Stir ◽  
T6 Heat Treatment ◽  
Az91c Magnesium Alloy

The corrosion behavior of as-cast AZ91C magnesium alloy was studied by performing friction stir processing (FSP) and FSP followed by solution annealing and then aging. Phase analysis, microstructural characterization, potentiodynamic polarization test and immersion tests were carried out to relate the corrosion behavior to the samples microstructure. The microstructural observations revealed the breakage and dissolution of coarse dendritic microstructure as well as the coarse secondary [Formula: see text]-Mg[Formula: see text]Al[Formula: see text] phase which resulted in a homogenized and fine grained microstructure (15[Formula: see text][Formula: see text]m). T6 heat treatment resulted in an excessive growth and dispersion of the secondary phases in the microstructure of FSP zone. The potentiodynamic polarization and immersion tests proved a significant effect of both FSP and FSP followed by T6 on increasing the corrosion resistance of the cast AZ91C magnesium alloy. Improve in corrosion resistance after FSP was attributed to grain refinement and elimination of segregations and casting defects which makes more adhesive passive layer. Increase in volume fraction of precipitations after T6 heat treatment is determined to be the main factor which stabilizes the passive layer at different polarization values and is considered to be responsible for increasing the corrosion resistance.

Microstructure and Corrosion Resistance of AZ80/Al Composite Plate Fabricated by Friction Stir Processing

2013 ◽  
Vol 747-748 ◽  
pp. 313-319 ◽  
Author(s):  
Fen Cheng Liu ◽  
Qiang Liu ◽  
Chun Ping Huang ◽  
Kun Yang ◽  
Cheng Gang Yang ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Friction Stir Processing ◽  
Composite Plate ◽  
Composite Layer ◽  
Electrochemical Corrosion ◽  
Friction Stir ◽  
Alloy Substrate ◽  
Corrosion Medium ◽  
Al Composite

AZ80/Al composite plate was fabricated by means of friction stir processing (FSP) aimed at the improvement of corrosion resistance of magnesium alloy. The cross-section microstructure, surface morphology and corrosion resistance of the Al composite layer were investigated. The experiment results indicated that a dense composite Al layer with superfine and uniform grains was formed, and a few amount of intermetallic compounds existed in the area of Mg/Al interface. The bonding strength of AZ80 magnesium alloy substrate and 1060 pure Al layer was proved to be high which was resulted from the metallurgical bonding of FSP. Microhardness measurement showed the continuous changing of microhardness values from the outmost surface of composite Al layer to the magnesium alloy substrate. Results of electrochemical corrosion test of the composite plate in 5 wt.% NaCl solution showed the better protection effect of the composite Al layer on the magnesium alloy in a corrosion medium. Almost the same corrosion level on the whole corrosion surface was observed which indicated the highly uniform microstructure of the composite layer. It was also proved that the plain arches on the outmost surface of the composite Al layer had no influence on the corrosion resistance of composite Al layer.

The Research of Micro Arc Oxidation Behavior of the Magnesium Alloy

2013 ◽  
Vol 803 ◽  
pp. 191-195
Author(s):  
Yun Long Zhang ◽  
Mu Qin Li ◽  
Yu Min Zhang ◽  
Ming Hu
Keyword(s):  
Corrosion Resistance ◽  
Phase Composition ◽  
Magnesium Alloy ◽  
Surface Morphology ◽  
Electrolyte Solution ◽  
Oxidation Behavior ◽  
Corrosion Current ◽  
Positive Potential ◽  
Micro Arc Oxidation ◽  
Oxidation Technology

The ceramics coating hadobtained by the micro arc oxidation technology in order to resolve thecorrosion resistance of the Mg alloy.The phase composition, surface morphology,gained weight and polarization behavior of the micro arc oxidation coating wasinvestigated in details. After the introduce of the sodiumcitrate in the electrolyte solution, thespecimen had high relatively positive potential and low corrosion current, sodoped sodium citratewould improve the corrosion resistance properties of the Mg alloy .

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