Surface Modification on Magnesium Alloys by Coating with Magnesium Fluorides

2005 ◽  
Vol 475-479 ◽  
pp. 505-508 ◽  
Author(s):  
T. Ohse ◽  
Harushige Tsubakino ◽  
Atsushi Yamamoto
Keyword(s):  
Corrosion Resistance ◽  
Surface Modification ◽  
Magnesium Alloy ◽  
Magnesium Alloys ◽  
Az31 Alloy ◽  
Immersion Test ◽  
Low Ph ◽  
Nacl Solution ◽  
Filiform Corrosion ◽  
A New Technique

A new technique has been developed for improving corrosion resistance on magnesium alloys. Specimens of AZ31 magnesium alloy were dipped into molten salt of NaBF4 at 723 K for various times, and then cooled, rinsed with water, and dried in air. Corrosion resistance in the surface treated specimens was evaluated by salt immersion test using 1 % NaCl solution as a time for occurring filiform corrosion. On an un-treated AZ31 alloy, the time for starting the filiform corrosion was about 1.2 ks, while on the surface treated specimen, the time was prolonged into about 1300 ks. Moreover, the surface treated specimen showed corrosion resistance in low pH solutions, such as 1 % HNO3 and HCl solutions.

Stress corrosion cracking behavior of micro-arc oxidized AZ31 alloy

2019 ◽  
Vol 234 (8) ◽  
pp. 1640-1652 ◽  
Author(s):  
Xiuli He ◽  
Hongyu Liang ◽  
Zhifeng Yan ◽  
Rui Bai
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Az31 Alloy ◽  
Corrosion Cracking ◽  
Nacl Solution ◽  
Cracking Behavior ◽  
Good Corrosion Resistance ◽  
Mixed Fracture

The stress corrosion cracking behaviors of micro-arc oxidized AZ31 magnesium alloy were studied by using the slow tensile test in air and 3.5 wt.% NaCl solution. Results showed that compared with the substrate, the stress corrosion cracking susceptibility of the micro-arc oxidized specimens was obvious improved apparently in 3.5 wt.% NaCl solution, due to the good corrosion resistance of the specimens after micro-arc oxidized coating treatment. In addition, regardless of the micro-arc oxidized treatment, it was the mixed fracture in air and the cleavage fracture in 3.5 wt.% NaCl solution. The micro-arc oxidized coating had no direct effect on the fracture mechanism of the alloy. It was closely related to the nature of the material and the environment of the material servicing.

The Corrosion Resistance of the Mg-Al-Ca-Sr Sand Casting Magnesium Alloys

2012 ◽  
Vol 326-328 ◽  
pp. 255-260 ◽  
Author(s):  
Andrzej Kiełbus ◽  
Tomasz Rzychoń ◽  
Joanna Michalska ◽  
Michal Stopyra
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Rate ◽  
Magnesium Alloys ◽  
Room Temperature ◽  
Immersion Test ◽  
Corrosion Layer ◽  
Sand Casting ◽  
Nacl Solution ◽  
Effective Barrier ◽  
Corrosion Rates

In this paper, the corrosion resistance of two sand-casting creep resistant magnesium alloys Mg-9Al-1.5Ca-0.3Sr and Mg-9Al-2.2Ca-0.8Sr in the salt environment has been investigated. Specimens of each alloy has been immersed in 3.5% NaCl solution at room temperature and successively taken out after 1, 2, 4, 5 and 9 days. After immersion test, the microstructure and the appearances of the corroded structure were examined. The corrosion rates of both investigated alloys increased lineally with increasing the exposure time in both solutions. Mg-9Al-1.5Ca-0.3Sr alloy exhibits the higher corrosion rate during the immersion test than Mg-9Al-2.2Ca-0.8Sr. The corrosion layer of both alloys consists of MgO, MgOH and phases containing Cl, Na, Al and Ca. The increase of Ca content in the Mg-9Al-2.2Ca-0.8Sr alloy improved the corrosion resistance due to the formation of the reticular (Mg,Al)2Ca phase, which acted as an effective barrier against corrosion.

scholarly journals Preparation and Characterization of Hydroxyapatite Coating on AZ31 Magnesium Alloy Induced by Carboxymethyl Cellulose-Dopamine

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1849
Author(s):  
Yanxia Yang ◽  
Yuanzhi Wu ◽  
Yu Wei ◽  
Tian Zeng ◽  
Baocheng Cao ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Magnesium Alloys ◽  
Carboxymethyl Cellulose ◽  
Az31 Alloy ◽  
Chloride Ions ◽  
Hydroxyapatite Coating ◽  
X Ray ◽  
Implant Materials ◽  
Good Biocompatibility

Magnesium and its alloys have become potential implant materials in the future because of light weight, mechanical properties similar to natural bone, good biocompatibility, and degradability in physiological environment. However, due to the rapid corrosion and degradation of magnesium alloys in vivo, especially in the environment containing chloride ions, the application of magnesium alloys as implant materials has been limited. Therefore, improving the corrosion resistance of magnesium alloy and ensuring good biocompatibility is the main focus of the current research. In this study, hydroxyapatite coating was prepared on magnesium alloy surface using carboxymethyl cellulose-dopamine hydrogel as inducer to improve corrosion resistance and biocompatibility. Surface characterization techniques (scanning electron microscopy, Fourier-transformed infrared spectroscopy, energy dispersive X-ray spectroscopy- and X-ray diffraction) confirmed the formation of hydroxyapatite on the surface of AZ31 alloy. Corrosion resistance tests have proved the protective effect of Carboxymethyl cellulose-Dopamine/hydroxyapatite (CMC-DA/HA) coating on the surface of AZ31 alloy. According to MC3T3-E1 cell viability and Live/Dead staining, the coating also showed good biocompatibility. The results will provide new ideas for the biological application of magnesium alloys.

Controlled release and corrosion protection by self-assembled colloidal particles electrodeposited onto magnesium alloys

2015 ◽  
Vol 3 (8) ◽  
pp. 1667-1676 ◽  
Author(s):  
Jiadi Sun ◽  
Ye Zhu ◽  
Long Meng ◽  
Wei Wei ◽  
Yang Li ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Controlled Release ◽  
Magnesium Alloys ◽  
Corrosion Protection ◽  
Colloidal Particles ◽  
Self Assembled ◽  
Bioactive Agents

Self-assembled nanoparticles loaded with bioactive agents were electrodeposited to provide the magnesium alloy with controlled release and corrosion resistance properties.

scholarly journals Study of ph effect on AZ31 magnesium alloy corrosion for using in temporary implants

2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Caio A. J. da Silva Da Silva ◽  
Lilian N. M. Braguin ◽  
Larissa O. Berbel ◽  
Bárbara V. G. De Viveiros ◽  
Jesualdo L. Rossi ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Body Fluid ◽  
Ph Effect ◽  
Az31 Alloy ◽  
Corrosion Process ◽  
Az31 Magnesium Alloy ◽  
Nacl Solution ◽  
Agar Gel ◽  
Ph Variation ◽  
Elemental Chemical Analysis

Currently, magnesium alloys are gaining great interest for medical applications due to their degrading properties in the human body ensuring a great biocompatibility. These alloys also provide profitable mechanical properties due similarities with human bone.  However, a difficulty in applying these materials in the biomaterials industries is the corrosion prior to cell healing. The effect of the chemical composition of Mg alloys on their corrosion behavior is well known. In this study, samples of AZ31 magnesium alloy were cut into chips for elemental chemical analysis by neutron activation analysis (NAA). Concentrations of the elements As, La, Mg, Mn, Na, Sb and Zn were determined in the AZ31 alloy. Visualization tests of agar corrosion development in various media, of 0.90% sodium chloride solution (mass), phosphate buffer saline (PBS) and simulated body fluid (SBF) were performed. Visualizations of the effect of agar gel corrosion revealed pH variation during the corrosion process due to the released into the cathode. The highest released of hydroxyl ions occurred in NaCl solution compared to PBS and SBF solutions indicating that NaCl solution was much more aggressive to the alloy compared to the others.

Effects of Erbium Addition on the Corrosion Resistance and Microstructure of AZ91 Magnesium Alloy

2011 ◽  
Vol 194-196 ◽  
pp. 1221-1224 ◽  
Author(s):  
Zhong Jun Wang ◽  
Yang Xu ◽  
Jing Zhu
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Magnesium Alloys ◽  
Discontinuous Precipitation ◽  
Az91 Magnesium Alloy ◽  
Continuous Precipitation ◽  
Az91 Magnesium ◽  
Precipitation Phase

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.

Catechol/polyethyleneimine conversion coating with enhanced corrosion protection of magnesium alloys: potential applications for vascular implants

2018 ◽  
Vol 6 (43) ◽  
pp. 6936-6949 ◽  
Author(s):  
Hao Zhang ◽  
Lingxia Xie ◽  
Xiaolong Shen ◽  
Tengda Shang ◽  
Rifang Luo ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Surface Modification ◽  
Magnesium Alloys ◽  
Corrosion Protection ◽  
Conversion Coating ◽  
Good Corrosion Resistance ◽  
Potential Applications

A catechol/polyethyleneimine conversion coating on a MgZnMn alloy possessed good corrosion resistance. Heparin was further grafted on it and this showed the potential for surface modification of magnesium-based vascular implants.

Corrosion and Protection of Magnesium Alloys

2015 ◽  
Vol 1120-1121 ◽  
pp. 1078-1082 ◽  
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.

INFLUENCE OF SURFACTANTS ON THE CORROSION PROPERTIES OF CHROMIUM-FREE ELECTROLESS NICKEL DEPOSIT ON MAGNESIUM ALLOY

2012 ◽  
Vol 19 (03) ◽  
pp. 1250025 ◽  
Author(s):  
JOTHI SUDAGAR ◽  
RUAN DEWEN ◽  
YAQIN LIANG ◽  
RASU ELANSEZHIAN ◽  
JIANSHE LIAN
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Electroless Nickel ◽  
Corrosion Current ◽  
Immersion Test ◽  
Electrochemical Polarization ◽  
Nickel Deposit ◽  
Corrosion Properties ◽  
Positive Direction ◽  
Polarization Test

Influence of surfactants on the corrosion properties of chromium-free electroless nickel deposit were investigated on AZ91D magnesium alloy. The corrosion tests were carried out by immersion test (1 M HCl) and electrochemical polarization test (3.5 wt% NaCl ). The surfactants in the electroless nickel bath increases the corrosion resistance properties of the deposit on the magnesium alloy. In addition, smoothness and amorphous plus nano-crystalline phase were increased and accounted for the significant corrosion resistance. As a consequence, the corrosion potential moved towards the positive direction and the corrosion current density decreased. The immersion tests also provided the same trend as that of electrochemical polarization test. On the whole, the study concluded that corrosion resistance was enhanced by including a surfactant in the electroless deposits on magnesium alloy.

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