Characteristic and Corrosion Studies of Rare Earth (REE) Based Anodizing on AZ91D Magnesium Alloy

2013 ◽  
Vol 594-595 ◽  
pp. 571-574
Author(s):  
Mat Akhir Khalid Azadi ◽  
M.Z.M. Zamzuri ◽  
S. Norbahiyah ◽  
Mohd Nazree Derman
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Immersion Test ◽  
Optical Microscope ◽  
Oxide Coatings ◽  
Az91d Magnesium Alloy ◽  
Β Phase ◽  
Corrosion Studies ◽  
Corrosion Behaviors ◽  
Scanning Electron

Oxide coatings on AZ91D magnesium alloy were prepared using anodizing technique with 10mA/cm2 current density for 5 minutes in electrolyte containing Mg (NO3)2 with NaVO3 as an additive. The corrosion behaviors of different coatings condition were evaluated by immersion test in 5.0% NaCl electrolyte for 72 hours. The microstructures were analyzed by Optical Microscope (OM) and Scanning Electron Microscope (SEM). It was found that coatings with the addition of NaVO3 produced homogeneous primary α-matrix and bigger β-phase (Mg17Al12) compared to untreated AZ91D magnesium alloy. The oxide film formed by anodizing in electrolyte with NaVO3 enhances the corrosion resistance of the AZ91D magnesium alloy significantly.

Characteristic and Corrosion Studies of Rare Earth (Ree) Based Anodizing on AZ91D Magnesium Alloy

2014 ◽  
Vol 879 ◽  
pp. 38-42
Author(s):  
Mat Akhir Khalid Azadi ◽  
M.Z.M. Zamzuri ◽  
S. Norbahiyah ◽  
M.R.N. Liyana ◽  
M. Marina ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Immersion Test ◽  
Optical Microscope ◽  
Oxide Coatings ◽  
Az91d Magnesium Alloy ◽  
Β Phase ◽  
Corrosion Studies ◽  
Corrosion Behaviors ◽  
Scanning Electron

Oxide coatings on AZ91D magnesium alloy were prepared using anodizing technique with 10mA/cm2 current density for 5 minutes in electrolyte containing La (NO3) and Mg (NO3),with NaVO3 as an additive. The corrosion behaviors of different coatings condition were evaluated by immersion test in 5.0% NaCl electrolyte for 72 hours. The microstructures were analyzed by Optical Microscope (OM) and Scanning Electron Microscope (SEM). It was found that coatings with the addition of NaVO3 produced homogeneous primary α-matrix and bigger β-phase (Mg17Al12) compared to untreated AZ91D magnesium alloy. The oxide film formed by anodizing in electrolyte with NaVO3 enhances the corrosion resistance of the AZ91D magnesium alloy significantly

Effect of NaVO3 Concentration on Corrosion Resistance of Conversion Coating on AZ91D Magnesium Alloy

2012 ◽  
Vol 576 ◽  
pp. 438-441 ◽  
Author(s):  
N.F.W.M. Sidik ◽  
M.Z.M. Zamzuri ◽  
M. Mat Salleh ◽  
Khairul Azwan Ismail
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Oxide Films ◽  
Chemical Conversion ◽  
Immersion Test ◽  
Optical Microscope ◽  
Conversion Coating ◽  
Energy Dispersive Analysis ◽  
Az91d Magnesium Alloy ◽  
Superior Corrosion Resistance

Anticorrosive oxide films were successfully prepared on AZ91D magnesium alloy by chemical conversion coating in La (NO3)3 electrolytes with and without NaVO3. The morphologies and chemical composition were characterized by optical microscope, scanning electron microscope (SEM) and energy dispersive analysis (EDX). The corrosion resistances of the oxide films were evaluated by salt immersion test. The result showed that the oxide film formed in electrolyte with NaVO3 is successful in providing superior corrosion resistance for AZ91D magnesium alloy.

Corrosion Resistance by Sodium Metavanadate for AZ91D Magnesium Alloy

2014 ◽  
Vol 575 ◽  
pp. 170-174 ◽  
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.

Improvement of Corrosion Resistance of Rare Earth Element (REE)-Based Anodic Oxidation Coating on AZ91D Magnesium Alloy

2012 ◽  
Vol 187 ◽  
pp. 210-214 ◽  
Author(s):  
M.Z.M. Zain ◽  
S. Illias ◽  
M. Mat Salleh ◽  
K. Azwan Ismail ◽  
Z. Nooraizedfiza
Keyword(s):  
Corrosion Resistance ◽  
Rare Earth ◽  
Magnesium Alloy ◽  
Anodic Oxidation ◽  
Earth Metal ◽  
Immersion Test ◽  
Corrosion Property ◽  
Anodic Film ◽  
Anodic Films ◽  
Az91d Magnesium Alloy

Anodization is a useful technique for forming protective films on magnesium alloys and improves its corrosion resistance. Based on the rare earth metal (REE) salt solution, the optimum parameter was selected by comparing the anti-corrosion property of anodic film. The structure, component and surface morphology of anodic film and cross-section were analyzed using X-ray diffraction (XRD) and scanning electron microscopy (SEM) coupled with Energy Dispersive Spectroscopy (EDS). The corrosion behavior was evaluated by immersion test. In this paper, a dense anodic film approximately 20 µm thick was prepared on a AZ91D magnesium alloy through anodic oxidation coating. The results show that the anodic films were mainly composed of Mg17Al12, Mg17La2, MgO and amorphous compounds. The best corrosion resistance was obtained with specimen anodized in solution containing both lanthanum nitrate and magnesium, whose corrosion resistance is approximately 3 times higher than that of as-received AZ91D magnesium alloy.

Effect of Ti Addition on Corrosion Properties of As-Cast and Hot-Rolled AM60 Magnesium Alloys

2017 ◽  
Vol 750 ◽  
pp. 113-117
Author(s):  
Yavuz Sun ◽  
Nazif Ugur Aydın ◽  
Yunus Turen ◽  
Hayrettin Ahlatci ◽  
Huseyin Zengin
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Immersion Test ◽  
Electrochemical Analysis ◽  
Electrochemical Test ◽  
Corrosion Properties ◽  
Homogenization Treatment ◽  
Corrosion Behaviors ◽  
Hot Rolled ◽  
Ti Addition

This study investigates the effect of Ti addition (0, 0.2, 0.5, 1wt%) on corrosion resistance of as-cast and hot rolled AM60 magnesium alloy. Corrosion behaviors were investigated by immersion tests and electrochemical analysis. The results showed that Ti addition altered the microstructure of as-cast AM60 magnesium alloy by decreasing the amount of β-Mg17Al12 eutectic phase. Homogenization treatment resulted in the dissolution of the most of the β-Mg17Al12 phases. Homogenized samples exhibited the lowest corrosion rate in immersion test while the best corrosion resistance was found for hot-rolled samples in electrochemical test. In hot-rolled state, Ti addition led to a slight change in the corrosion resistance of AM60 magnesium alloy.

CORROSION MECHANISM AND MODEL OF ANODIZED FILM ON AZ91D MAGNESIUM ALLOY

2010 ◽  
Vol 24 (15n16) ◽  
pp. 3077-3082 ◽  
Author(s):  
LINA LI ◽  
JIANGANG QIAN ◽  
ZHAOZHONG LU ◽  
ZHONGWU SUN
Keyword(s):  
Magnesium Alloy ◽  
Immersion Time ◽  
Immersion Test ◽  
Corrosion Mechanism ◽  
Nacl Solution ◽  
Az91d Magnesium Alloy ◽  
Β Phase ◽  
Α Phase ◽  
Corrosion Reaction ◽  
Neutral Aqueous Solution

The corrosion behavior of anodized film on AZ91D magnesium alloy in 3.5% neutral NaCl solution was investigated by saline immersion test. The results show that new corrosion points seldom occur on the surface of the said anodized film during the immersion time in 3.5% NaCl neutral aqueous solution after the first macroscopic corrosion point appears on the anodized film, while the previous corrosion point extends vertically or horizontally and turns into a corrosion pit which is in form of "strip". Moreover, the corrosion occurs firstly on α phase rather than β phase, when the corrosion of anodized film reaches the Mg alloy substrate. The corrosion products of anodized film on AZ91D magnesium alloy in neutral immersion solution were analyzed by XRD. A possible corrosion reaction and model about the corrosion of anodized film on AZ91D magnesium alloy in NaCl solution based on the experimental results is proposed.

scholarly journals Corrosion resistance of the microarc oxidation coatings prepared on magnesium alloy

2018 ◽  
Vol 38 ◽  
pp. 02009
Author(s):  
Ying Lv ◽  
Jun Gang Li ◽  
Ming Zhong Wu ◽  
Zhen Ma ◽  
Jing Qiang Zhang ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Microarc Oxidation ◽  
Electrochemical Corrosion ◽  
Ceramic Coatings ◽  
Nacl Solution ◽  
Oxide Coatings ◽  
Az91d Magnesium Alloy ◽  
Oxidation Technology ◽  
Electrochemical Corrosion Resistance

Ceramic coatings were prepared on the surface of AZ91D magnesium alloy by microarc oxidation technology. The effects of different voltages on morphology, phase composition and thickness of the coatings were characterized by SEM and XRD. The corrosion resistance of the coatings was measured by electrochemical workstation. Results indicated that the microarc oxidation coatings prepared in sodium silicate electrolyte exhibited porous surface and mainly comprised MgO, Mg2SiO4 and a small amount of MgAl2O4. The thickness of the oxide coatings increased rapidly with the increase of voltage. The coating prepared at 400V voltage had good electrochemical corrosion resistance in 3.5wt% NaCl solution.

Study of the Correlation between Microstructure and Corrosion Resistance of the AZ91D Magnesium Alloy

2018 ◽  
Vol 930 ◽  
pp. 405-410 ◽  
Author(s):  
Renato Altobelli Antunes ◽  
Mara Cristina Lopes de Oliveira ◽  
Lucas Costa de Castro Ferraz ◽  
Letícia dos Reis Gonçales ◽  
Olandir Vercino Correa
Keyword(s):  
Electron Microscopy ◽  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Volume Fraction ◽  
Beta Phase ◽  
Alpha Phase ◽  
Solution Annealing ◽  
Az91d Magnesium Alloy ◽  
Phase Solution ◽  
Scanning Electron

The aim of the present work was to study the influence of beta phase precipitates content and distribution on the corrosion behavior of the AZ91D magnesium alloy, using samples subjected to solution annealing and aging. The morphology of the beta phase was observed using optical microscopy and scanning electron microscopy. The volume fraction of each phase was also determined. Potentiodynamic polarization tests and immersion tests were carried out, indicating an increase of the corrosion resistance with the volume fraction of the beta phase and its distribution on the grain boundaries of the alpha-phase. Solution annealed samples were more susceptible to corrosion.

scholarly journals Corrosion and Tensile Behaviors of Ti-4Al-2V-1Mo-1Fe and Ti-6Al-4V Titanium Alloys

Metals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1213 ◽  
Author(s):  
Yanxin Qiao ◽  
Daokui Xu ◽  
Shuo Wang ◽  
Yingjie Ma ◽  
Jian Chen ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Low Cost ◽  
Tensile Tests ◽  
Nacl Solution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Β Phase ◽  
Mass Losses ◽  
Corrosion Behaviors ◽  
Scanning Electron

X-ray diffraction (XRD), scanning electron microscope (SEM), immersion, electrochemical, and tensile tests were employed to analyze the phase constitution, microstructure, corrosion behaviors, and tensile properties of a Ti-6Al-4V alloy and a newly-developed low cost titanium alloy Ti-4Al-2V-1Mo-1Fe. The results showed that both the Ti-6Al-4V and Ti-4Al-2V-1Mo-1Fe alloys were composed of α and β phases. The volume fractions of β phase for these two alloys were 7.4% and 47.3%, respectively. The mass losses after 180-day immersion tests in 3.5 wt.% NaCl solution of these alloys were negligible. The corrosion resistance of the Ti-4Al-2V-1Mo-1Fe alloy was higher than that of the Ti-6Al-4V alloy. The tensile tests showed that the Ti-4Al-2V-1Mo-1Fe alloy presented a slightly higher strength but a lower ductility compared to the Ti-6Al-4V alloy.

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