scholarly journals Corrosion Behavior and Biological Activity of Micro Arc Oxidation Coatings with Berberine on a Pure Magnesium Surface

Coatings ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 837
Author(s):  
Liting Mu ◽  
Zhen Ma ◽  
Jingyan Wang ◽  
Shidan Yuan ◽  
Muqin Li
Keyword(s):  
Biological Activity ◽  
Current Density ◽  
Photoelectron Spectroscopy ◽  
Corrosion Current Density ◽  
Electrochemical Impedance ◽  
Corrosion Current ◽  
Pure Magnesium ◽  
X Ray ◽  
Micro Arc Oxidation ◽  
Assembly Technology

Bone tissue repair materials can cause problems such as inflammation around the implant, slow bone regeneration, and poor repair quality. In order to solve these problems, a coating was prepared by ultrasonic micro-arc oxidation and self-assembly technology on a pure magnesium substrate. We studied the effect of berberine on the performance of the ultrasonic micro-arc oxidation/polylactic acid and glycolic acid copolymer/berberine (UMAO/PLGA/BR) coating. The chemical and morphological character of the coating was analyzed using scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The corrosion properties were studied by potentiodynamic polarization and electrochemical impedance spectroscopy in a simulated body fluid. The cumulative release of drugs was tested by high-performance liquid chromatography. The results indicate that different amounts of BR can seal the corrosion channel to different extents. These coatings have a self-corrosion current density (Icorr) at least one order of magnitude lower than the UMAO coatings. When the BR content is 3.0 g/L, the self-corrosion current density of the UMAO/PLGA/BR coatings is the lowest (3.14 × 10−8 A/cm2) and the corrosion resistance is improved. UMAO/PLGA/BR coatings have excellent biological activity, which can effectively solve the clinical problem of rapid degradation of pure magnesium and easy infection.

Electrochemical Characteristics of Al-Based Coating on Magnesium Alloy Fabricated by Supersonic Particles Deposition

2013 ◽  
Vol 756-759 ◽  
pp. 85-88
Author(s):  
Xiao Ming Wang ◽  
Sheng Zhu ◽  
Qing Chang ◽  
Guo Feng Han
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Magnesium Alloy ◽  
Impedance Spectroscopy ◽  
Current Density ◽  
Corrosion Current Density ◽  
Corrosion Potential ◽  
Electrochemical Impedance ◽  
Corrosion Current ◽  
Electrochemical Characteristics ◽  
Order Of Magnitude

Al-based coating on ZM5 magnesium alloy was prepared by Supersonic Particles Deposition (SPD). Electrochemical working station was utilized to test polarization curve, corrosion potential and electrochemical impedance spectroscopy etc. The results indicted that corrosion potential of Al-Si coating was about-767.6mV, much higher than that of ZM5 Mg-substrate; And corrosion current density of the coating sample decreased three order of magnitude than that of the uncoated. Compared to Mg-substrate, the radius of capacitive impedance arc of the coating enlarged and impedance modulus improved two order of magnitude.

Electrochemical performances of pyrolytic-cellulose for lithium and sodium ion batteries anode

2020 ◽  
Vol 10 (10) ◽  
pp. 1685-1691
Author(s):  
Lingfang Li ◽  
Dan Chen ◽  
Sichao Su ◽  
Bin Zeng
Keyword(s):  
Current Density ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
High Current Density ◽  
Energy Storage Materials ◽  
Electrochemical Performances ◽  
Hard Carbon ◽  
X Ray ◽  
Sodium Storage ◽  
Charge Discharge

At present, due to the depletion of fossil fuels and increasingly serious environmental problems, more and more attention has been paid to the development and application of functional nanostructured materials as renewable energy storage materials. Herein, lithium and sodium storage properties of hard carbons (HC) prepared by pyrolyzing cellulose were investigated. The orderliness and bonding mode of hard carbon were analyzed by X-Ray Diffraction and X-ray Photoelectron Spectroscopy. Electrochemical properties were characterized by Cyclic Voltammetry, electrochemical Impedance Spectroscopy and charge–discharge test. Results showed that the cellulose-derived hard carbon had good lithium and sodium storage performance. The charge–discharge capacity was about 400 mAh/g and 240 mAh/g, respectively, at a current density of 0.2 A/g, and capacity was also stable under high current density of 2 A/g.

Corrosion Resistance of Mg-4Zn Alloy with Amorphous Micro-Arc Oxidation Coating in Simulated Body Fluid

2016 ◽  
Vol 852 ◽  
pp. 1325-1333
Author(s):  
Li Chen Zhao ◽  
Shuang Jin Liu ◽  
Yu Min Qi ◽  
Chun Xiang Cui
Keyword(s):  
Corrosion Resistance ◽  
Simulated Body Fluid ◽  
Current Density ◽  
Polarization Resistance ◽  
Body Fluid ◽  
Corrosion Current Density ◽  
Corrosion Current ◽  
Metal Substrate ◽  
Electrochemical Measurements ◽  
Micro Arc Oxidation

A binary Mg-4Zn alloy was fabricated as a potential degradable biomaterial. To improve the corrosion resistance of Mg-4Zn alloy, an amorphous micro-arc oxidation (MAO) coating was prepared on the Mg-4Zn substrate. Electrochemical measurements and immersion tests were employed to evaluate the corrosion resistance of the specimen in simulated body fluid (SBF). Electrochemical measurements show that the Mg-4Zn alloy covered with a MAO coating has a much lower corrosion current density and a much greater polarization resistance. Immersion tests suggest that the degradation of Mg-4Zn substrate is relatively serious during the initial 8 h of immersion although it has been protected by a MAO coating. When most micro-pores within the MAO coating have been filled with precipitates resulted from the corrosion of the metal substrate, the degradation of the Mg-4Zn substrate is significantly delayed.

Effects of CeO2 on Microstructure and Corrosion Performance of the Coatings Prepared by Pulse Micro Arc Oxidation on AZ31B Mg Alloy

2020 ◽  
Vol 20 (8) ◽  
pp. 4778-4786
Author(s):  
Lilu Qin ◽  
Jiamu Huang ◽  
Longlong Hao ◽  
Jun Su ◽  
Niu Ma ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Current Density ◽  
Corrosion Current Density ◽  
Corrosion Potential ◽  
Salt Spray ◽  
Electrochemical Measurement ◽  
Corrosion Current ◽  
Corrosion Performance ◽  
Micro Arc Oxidation ◽  
Micro Morphology

To improve corrosion performance of coatings on AZ31B magnesium alloy, the nano-CeO2 additives were included in Na2SiO3 based electrolyte during process of pulse micro arc oxidation (MAO). The MAO-CeO2 coating was successfully prepared to characterize its structure, micro morphology and composition. The XRD results indicated that MAO-CeO2 coatings were consisted of Mg2SiO4, MgSiO3, MgF2 and CeO2. The intensity of CeO2 peaks increases with increasing nano-CeO2 particles in electrolyte. The number of cracks on MAO-CeO2 coatings exhibited a V-shaped trend with increase in nano-CeO2 content. Meanwhile, the influence of nano-CeO2 on corrosion behavior of MAO-CeO2 coatings is investigated by salt spray test and electrochemical measurement. The corrosion current density of coatings presented same trend and corrosion potential is further studied. The MAO-CeO2 coatings formed in electrolyte with 10 g/L nano-CeO2 showed best corrosion performance which has the lowest corrosion current density of 0.58 nA/cm2 and the highest corrosion potential of - 1269 mVSCE.

Hydrothermal synthesis of PANI nanowires for high-performance supercapacitor

2019 ◽  
Vol 32 (3) ◽  
pp. 258-267 ◽  
Author(s):  
Jia Chu ◽  
Xue Li ◽  
Qiaoqin Li ◽  
Jing Ma ◽  
Bohua Wu ◽  
...  
Keyword(s):  
Specific Capacitance ◽  
Current Density ◽  
Photoelectron Spectroscopy ◽  
High Performance ◽  
Electrochemical Impedance ◽  
Scanning Electron Micrographs ◽  
X Ray ◽  
Different Temperatures ◽  
Polyaniline Nanowires ◽  
Charge Discharge

Polyaniline nanowires (PANI NWs) were synthesized under different temperatures through a facile hydrothermal method and used as electrodes for high-performance pseudocapacitor. The resulting samples were analyzed by X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy, scanning electron micrographs, thermogravimetric analysis, and X-ray photoelectron spectroscopy. Electrochemical properties of these PANI electrodes are studied by cyclic voltammetry, galvanostatic charge–discharge test, and electrochemical impedance spectroscopy in 0.5M H2SO4 aqueous solution. The highest specific capacitance is obtained on the PANI NWs synthesized under 80°C (PANI-80) with 540.0 F g−1 at current density of 0.5 A g−1 accompanied with 82% specific capacitance retention after 1000 charge discharge cycles at 5 A g−1 current density.

Electrochemical Corrosion Behavior of Iron Aluminides in Sulfuric Acid

2020 ◽  
Vol 1012 ◽  
pp. 395-400
Author(s):  
Pedro Paiva Brito ◽  
Carlos Trivellato de Carvalho Filho ◽  
Gabriela de Andrade Oliveira
Keyword(s):  
Current Density ◽  
Corrosion Current Density ◽  
Electrochemical Impedance ◽  
Electrochemical Corrosion ◽  
Corrosion Current ◽  
Passive Behavior ◽  
Corrosion Evaluation ◽  
Electrochemical Corrosion Behavior ◽  
Work Samples ◽  
Passive Current

In the present work, samples of a binary intermetallic alloy (Fe3Al) with 26at.%Al were submitted to electrochemical corrosion evaluation in a 0.5M H2SO4 solution containing naturally dissolved oxygen. The corrosion resistance was evaluated by applying linear polarization, electrochemical impedance spectroscopy and potentiodynamic polarization at 22 and 35°C. The results obtained revealed that in both conditions the material exhibits active-passive behavior. Heating to 35°C did not alter the passivity characteristics of the alloy (passivation range and passive current density), but elevated the corrosion current density and the critical current density. The polarization resistance of the samples was also decreased with temperature, following the trend observed for the corrosion current density.

High corrosion resistance Ni-reduced graphene oxide nanocomposite coating

2016 ◽  
Vol 34 (5-6) ◽  
pp. 305-312 ◽  
Author(s):  
Seyed Ali Hosseini Khorasani ◽  
Sohrab Sanjabi
Keyword(s):  
Corrosion Resistance ◽  
Graphene Oxide ◽  
Composite Coating ◽  
Current Density ◽  
Corrosion Current Density ◽  
Electrochemical Impedance ◽  
Corrosion Current ◽  
Nanocomposite Coating ◽  
High Corrosion Resistance ◽  
High Corrosion

AbstractThis paper presents a high corrosion resistance Ni-graphene composite coating fabricated by co-electrodeposition on Cu substrate. First, GO was synthesized by improved Hummers’ method, and then different concentrations of GO aqueous solution were introduced to Ni Watt’s bath. During electrodeposition, GO and Ni ions were reduced simultaneously to form composite coating. The phase structure and morphology were covered by X-ray diffraction and scanning electron microscopy analysis, respectively. Atomic force microscopy (AFM) was employed to identify the surface topography of the coatings. Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), and electrochemical impedance spectroscopy (EIS) were used to study the synthesis of GO and its reduction during the plating process. Corrosion resistance of nanocomposite and that of pure Ni coating were compared by applying potentiodynamic polarization spectroscopy (PDS). The results showed that by increasing the amount of graphene oxide in solution, there has been a significant reduction in corrosion current density. As the EIS result showed, the high amount of GO reduction was obtained in GO concentration of 0.6 mg ml−1 and current density of 8 A dm−2. It is in a good agreement with data obtained from PDS. Analyses showed that the corrosion current density of corresponding coating was improved up to 0.2 μA cm−2, which means an improvement of about 100 times compared to pure Ni coating.

Corrosion Behavior of Cobalt Alloy Coating in NaCl Solution

2020 ◽  
Vol 993 ◽  
pp. 1086-1094
Author(s):  
Yue Hou ◽  
Hai Yan Chen ◽  
Li Fan ◽  
Yu Rong Xu ◽  
Qian Cheng ◽  
...  
Keyword(s):  
Current Density ◽  
Corrosion Current Density ◽  
Electrochemical Impedance ◽  
Corrosion Behaviour ◽  
Alloy Coating ◽  
Corrosion Current ◽  
Eutectic Structure ◽  
Open Circuit ◽  
The Self ◽  
Nacl Solution

Two kinds of Co-based coatings were obtained through the laser cladding (LC) and plasma transfer arc (PTA) process. The phase composition and microstructure of the coatings were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The corrosion behaviour of the different Co-based alloy coatings in 3.5wt% NaCl solution were compared by means of open-circuit potential (OCP), polarization curve and electrochemical impedance spectroscopy (EIS). XRD and SEM measurements demonstrated that the microstructures of the two different Co-based coatings were composed of primary solid solution γ-Co and eutectic structure Cr23C6, whereas, fish-bone typed (CoCrW)6C was also detected in the coating produced by PTA. The polarization curves and EIS results showed that in 3.5wt% NaCl solution, the passivation zones of the two coatings occurred obviously, the self-corrosion potential of the two coatings shifted to the right, and the self-corrosion current density was much smaller than that of the substrate. In addition, the Co-based coating made by LC showed lower corrosion current density and larger diameter of a capacitive arc than that of Co-based coating produced by PTA, indicating the LC coating had the best corrosion resistance in the three samples.

scholarly journals Optimizing the Required Cathodic Protection Current for Pre-Buried Pipelines Using Electrochemical Acceleration Methods

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 579
Author(s):  
Nguyen-Thuy Chung ◽  
Min-Sung Hong ◽  
Jung-Gu Kim
Keyword(s):  
Current Density ◽  
Cathodic Protection ◽  
Potentiodynamic Polarization ◽  
Corrosion Current Density ◽  
Electrochemical Impedance ◽  
Operating Time ◽  
Corrosion Current ◽  
Buried Pipelines ◽  
Soil Corrosion ◽  
Surface Corrosion

Several corrosion mitigation methods are generally applied to pipelines exposed to corrosive environments. However, in the case of pre-buried pipelines, the only option for corrosion inhibition is cathodic protection (CP). To apply CP, the required current should be defined even though the pipeline is covered with various oxide layers. In this study, an electrochemical acceleration test was used to investigate the synthetic soil corrosion of a pre-buried pipeline. Potentiodynamic polarization experiments were first conducted to ascertain the corrosion current density in the environment, and galvanostatic measurements were performed to accelerate corrosion according to the operating time. In addition, corrosion current density and the properties of the rust layer were investigated via potentiodynamic polarization tests and electrochemical impedance spectroscopy (EIS) tests. The variation in surface corrosion was subsequently analyzed via optical microscopy (OM) and X-ray diffraction (XRD) measurements. Finally, an empirical equation for the optimized CP current requirement, according to the pipeline service time, was derived. This equation can be applied to any corroded pipeline.

EFFECT OF KOH ON MICRO-ARC OXIDATION COATINGS OF 2A12 ALUMINUM ALLOYS IN CH3COONa–Na2WO4 ELECTROLYTE

2014 ◽  
Vol 21 (02) ◽  
pp. 1450026
Author(s):  
ZHAO QING LIN ◽  
HUI JUN YU ◽  
SI YU HE ◽  
YI NING HE ◽  
CHUAN ZHONG CHEN
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Current Density ◽  
Corrosion Current ◽  
Scratch Test ◽  
Ceramic Coatings ◽  
X Ray Diffraction ◽  
Electrolyte System ◽  
X Ray ◽  
Micro Arc Oxidation ◽  
Scanning Electron

The ceramic coatings were prepared on 2A12 alloy by micro-arc oxidation in CH 3 COONa – Na 2 WO 4 electrolyte system with different concentration of KOH added. The effects of KOH in this electrolyte on micromorphology, phase compositions, adhesion and corrosion resistance of the coatings were investigated by scanning electron microscope (SEM), X-ray diffraction (XRD), scratch test and electrochemistry workstation. The results show that KOH has a significant influence on the surface morphology, which can make the surface smoother. The adhesion of the coating becomes stronger with the increase of KOH in the electrolyte. The corrosion resistance of the coated specimen increases a lot compared with that of the substrate. And the lowest corrosion current density (I corr ) of the coating prepared in the electrolyte with KOH is about three orders of magnitude lower than that of the substrate.

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