scholarly journals Surface Treatment of Zn-Mn-Mg Alloys by Micro-Arc Oxidation in Silicate-Based Solutions with Different NaF Concentrations

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4289
Author(s):  
Shineng Sun ◽  
Guo Ye ◽  
Ziting Lu ◽  
Yuming Weng ◽  
Guofeng Ma ◽  
...  
Keyword(s):  
Surface Treatment ◽  
Corrosion Behavior ◽  
Biomedical Applications ◽  
Electrochemical Impedance ◽  
Mg Alloys ◽  
X Ray Diffraction ◽  
Submicron Scale ◽  
Micro Arc Oxidation ◽  
Hank’S Solution ◽  
Zn Alloys

Newly developed Zn-Mn-Mg alloys can be invoked as biomedical materials because of their excellent mechanical properties. However, the corrosion behavior of Zn-Mn-Mg alloys was still lacking in research. It had grown to be a hot research topic to improve the corrosion behavior of Zn alloys by surface treatment to meet the application of degradable Zn alloys in biomedical applications. Micro arc oxidation (MAO) is a simple and effective method to improve the corrosion behavior of the alloy. MAO coatings were successfully prepared on the surface of Zn-Mn-Mg alloys by MAO in silicate-based solutions with different NaF concentrations. The microstructure and phase composition of MAO coatings prepared on Zn-Mn-Mg alloys with different NaF concentrations in the electrolyte was examined by a scanning electron microscope and X-ray diffraction. The results showed that the MAO coatings are porous and mainly composed of ZnO. With the increasing NaF concentration in the electrolyte, the average thickness increases. The distribution of the micro/nanopores was uniform, and the pore size ranged from the submicron scale to several micrometers after MAO treatment in the electrolyte containing different concentrations of NaF. Potential dynamic polarization curves and electrochemical impedance spectroscopy were employed to assess the corrosion behavior of MAO coatings in Hank’s solution. The highest corrosion rate can be achieved after MAO treatment, with an electrolyte concentration of 1.5 g/L NaF in Hank’s solution. These results indicated that MAO coating can accelerate the corrosion resistance of a Zn-Mn-Mg alloy.

Effect of Zn Content on Structure, Roughness and Corrosion Behavior of Zn-Ni Alloys

2019 ◽  
Vol 17 (17) ◽  
pp. 17-22
Author(s):  
Hayette Faid
Keyword(s):  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Stripping Voltammetry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ni Alloys ◽  
Sulfate Bath ◽  
Zn Content ◽  
Polarization Test ◽  
Δ Phase

AbstractIn this work, Zn-Ni alloys have been deposited on steel from sulfate bath, by electrodeposition method. The effect of Zn content on deposits properties was studied by cyclic voltammetry (CV), chronoaperometry (CA), linear stripping voltammetry (ALSV) and diffraction (XRD) and scanning electronic microscopy (SEM). The corrosion behavior in 3.5 wt. NaCl solution was examined using anodic polarization test and electrochemical impedance spectroscopy. X-ray diffraction of show that Zn-Ni alloys structure is composed of δ phase and γ phase, which increase with the decrease of Zn content in deposits. Results show that deposits obtained from bath less Zn2+ concentration exhibited better corrosion resistance.

scholarly journals Effect of Graphene Oxide Concentration in Electrolyte on Corrosion Behavior of Electrodeposited Zn–Electrochemical Reduction Graphene Composite Coatings

Coatings ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 758 ◽  
Author(s):  
Yang ◽  
Zhang ◽  
Wang ◽  
Wang ◽  
Chen ◽  
...  
Keyword(s):  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Composite Coatings ◽  
Laser Raman Spectroscopy ◽  
304 Stainless Steel ◽  
Sulfate Electrolyte ◽  
X Ray Diffraction ◽  
X Ray ◽  
Tafel Polarization ◽  
Laser Raman

Pure Zn and Zn–ERGO composite coatings were prepared by direct current electrodeposition on 304 stainless steel. Samples were characterized by X-ray diffraction (XRD), scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM/EDS), and laser Raman spectroscopy (Raman). Results obtained have shown that the concentration of GO sheets in zinc sulfate electrolyte has an important effect on the preferred crystal orientation and the surface morphology of Zn–ERGO composite coatings. A study of the corrosion behavior of the coatings by Tafel polarization and electrochemical impedance spectroscopic (EIS) methods leads to the conclusion that the Zn-1.0 g/L ERGO composite coating possesses the best corrosion resistance compared to the pure Zn coating and other composite coatings in this study.

scholarly journals Effect of Rare Earth Oxides on Microstructure and Corrosion Behavior of Laser-Cladding Coating on 316L Stainless Steel

Coatings ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 636 ◽  
Author(s):  
Xu ◽  
Wang ◽  
Chen ◽  
Qiao ◽  
Zhang ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Rare Earth ◽  
Corrosion Behavior ◽  
Laser Cladding ◽  
316L Stainless Steel ◽  
Electrochemical Impedance ◽  
Salt Spray ◽  
Rare Earth Oxides ◽  
X Ray Diffraction ◽  
X Ray

The effect of rare earth oxides on the microstructure and corrosion behavior of laser-cladding coating on 316L stainless steel was investigated using hardness measurements, a polarization curve, electrochemical impedance spectroscopy (EIS), a salt spray test, X-ray diffraction, optical microscopy, and scanning electron microscopy (SEM). The results showed that the modification of rare earth oxides on the laser-cladding layer caused minor changes to its composition but refined the grains, leading to an increase in hardness. Electrochemical and salt spray studies indicated that the corrosion resistance of the 316L stainless steel could be improved by laser cladding, especially when rare earth oxides (i.e., CeO2 and La2O3) were added as a modifier.

Improvement of corrosion resistance of magnesium alloys for biomedical applications

2015 ◽  
Vol 33 (3-4) ◽  
pp. 101-117 ◽  
Author(s):  
Kai Chen ◽  
Jianwei Dai ◽  
Xiaobo Zhang
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Biomedical Applications ◽  
Mg Alloys ◽  
Localized Corrosion ◽  
Biodegradable Implants ◽  
Ordered Structure ◽  
Corrosion Rates ◽  
Long Period ◽  
Treatment Techniques

AbstractIn recent years, magnesium (Mg) alloys have attracted great attention due to superior biocompatibility, biodegradability, and other characteristics important for use in biodegradable implants. However, the development of Mg alloys for clinical application continues to be hindered by high corrosion rates and localized corrosion modes, both of which are detrimental to the mechanical integrity of a load-bearing temporary implant. To overcome these challenges, technologies have been developed to improve the corrosion resistance of Mg alloys, among which surface treatment is the most common way to enhance not only the corrosion resistance, but also the bioactivity of biodegradable Mg alloys. Nevertheless, surface treatments are unable to fundamentally solve the problems of fast corrosion rate and localized corrosion. Therefore, it is of great importance to alter and improve the intrinsic corrosion behavior of Mg alloys for biomedical applications. To show the significance of the intrinsic corrosion resistance of biodegradable Mg alloys and attract much attention on this issue, this article presents a review of the improvements made to enhance intrinsic corrosion resistance of Mg alloys in recent years through the design and preparation of the Mg alloys, including purifying, alloying, grain refinement, and heat treatment techniques. The influence of long-period stacking-ordered structure on corrosion behavior of the biodegradable Mg alloys is also discussed.

Impedance Behavior of the Composite Coatings Prepared on Magnesium Alloy AZ91 in Simulated Seawater Solution

2014 ◽  
Vol 900 ◽  
pp. 526-530
Author(s):  
Wei Shang ◽  
Zhou Lan Yin ◽  
Yu Qing Wen ◽  
Xu Feng Wang
Keyword(s):  
Magnesium Alloy ◽  
Corrosion Protection ◽  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Composite Coatings ◽  
Sol Gel ◽  
Soaking Time ◽  
Magnesium Alloy Az91 ◽  
Micro Arc Oxidation ◽  
Simulated Seawater

The composite coatings were obtained on a magnesium alloy by micro-arc oxidation and sol-gel technique. Electrochemical impedance spectroscopy (EIS) was used to evaluate the corrosion behavior of MAO coating and composite coatings in a simulated seawater solution. The results show that corrosion behavior of the MAO coating and composite coatings are different at different immersion times. Corrosion protection of the MAO coating gradually weaken with the extension of soaking time, but corrosion protection of the composite coatings become stronger first and then weaken.

Microstructures and Various Properties of Hot-Extruded Mg-Zr-Ca Alloys for Biomedical Applications

2012 ◽  
Vol 232 ◽  
pp. 162-166 ◽  
Author(s):  
Ying Long Zhou ◽  
Dong Mei Luo ◽  
Yun Cang Li ◽  
Cui'e Wen ◽  
Peter D. Hodgson
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Biomedical Applications ◽  
Hot Extrusion ◽  
X Ray Diffraction ◽  
Cast Alloys ◽  
Orthopedic Applications ◽  
Potential Use ◽  
Compressive Tests

The microstructures, mechanical properties, corrosion behavior, and biocompatibility of hot-extruded Mg-Zr-Ca alloys have been investigated for potential use in orthopedic applications. The microstructures of the alloys are examined by X-ray diffraction analysis and optical microscopy. The mechanical properties of Mg-Zr-Ca alloys are determined from compressive tests, the corrosion behavior is studied using immersion tests, and biocompatibility is evaluated by cell growth factor using osteoblast-like SaOS2 cell. The experimental results indicate that the hot-extruded alloys have much higher compressive strength than the as-cast alloys and the human bone, and can offer good mechanical properties for orthopedic applications. The hot-extrusion significantly enhances corrosion resistance of the alloys. Among the alloys, the hot-extruded Mg-0.5Zr-1Ca and Mg-1Zr-1Ca alloys possess good combination of mechanical properties, corrosion resistance, and biocompatibility, suggesting that they have a great potential to be good candidates for orthopedic applications.

scholarly journals Corrosion Behavior of L245N Standard Steel in CO2 Saturated Brine under Flow Condition

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 880
Author(s):  
Ying Hu ◽  
Long Xin ◽  
Tingguang Liu ◽  
Yonghao Lu
Keyword(s):  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Galvanic Corrosion ◽  
Morphological Characteristics ◽  
X Ray Diffraction ◽  
Slow Increase ◽  
Corrosion Scale ◽  
The One ◽  
Standard Steel

The corrosion behavior of oilfield used L245N standard steel was tested in simulated oilfield solution by dynamic high-temperature autoclave. The corrosion products were characterized by using scanning electron microscopy (SEM), X-ray diffraction (XRD) and Electrochemical impedance spectroscopy (EIS) respectively. In addition, the corrosion rates and surface morphological characteristics of the steels after different exposure times were studied. The results showed that the corrosion rate decreased sharply and then increased with time in the high salinity flow solution, which was related to the formation of corrosion scale and the remaining cementite within it. At the beginning of the exposure time, the formed corrosion scale became thicker, resulting in a significant decrease of the corrosion rate. While with increasing time, on the one hand, the increased remaining cementite within corrosion scale facilitated the corrosion by the galvanic corrosion between the remaining cementite and the ferrite within the metal. On the other hand, the protective effect of corrosion scale formed on the remaining cementite skeleton declined due to the formation of large amounts of FexCa1−xCO3, which also promoted the corrosion rate of the steels, both these ways contributed to a slow increase of corrosion rate.

scholarly journals Tribological performance and corrosion behavior of CoCrMo alloy

2021 ◽  
Vol 16 (59) ◽  
pp. 129-140
Author(s):  
Hadda Rezzag ◽  
Latifa Kahloul ◽  
Hacène Chadli ◽  
Alima Mebrek ◽  
Adel Saoudi
Keyword(s):  
Corrosion Behavior ◽  
Positive Impact ◽  
X Ray Diffraction ◽  
Cocrmo Alloy ◽  
Electrochemical Tests ◽  
Powder Metallurgy Process ◽  
Lower Corrosion Rate ◽  
Hank’S Solution ◽  
Metallurgy Process ◽  
Cocrmo Alloys

The present work focuses on the Tribological properties and corrosion behavior evaluation of sintered CoCrMo alloy. The CoCrMo alloy was elaborated by Powder metallurgy process at various sintering temperatures (1200°C, 1250°C and 1300°C). The structural properties were characterized by X-ray diffraction and scanning electron microscopy. The tribological characteristics were measured using a dry disc-ball tribometer. The corrosion behavior of the samples was studied using different electrochemical tests in a simulated physiological environment (Hank’s solution). The obtained results show that higher sintering temperatures have a positive impact on the tribological behavior as well as the corrosion resistance of CoCrMo alloys. The sintered samples at 1300°C showed a better resistance to friction wear and a lower corrosion rate.

scholarly journals Corrosion and Biocompatibility of Pure Zn with a Micro-Arc-Oxidized Layer Coated with Calcium Phosphate

Coatings ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1425
Author(s):  
Yixuan Shi ◽  
Lijing Yang ◽  
Lucai Wang ◽  
Qingke Zhang ◽  
Xinglong Zhu ◽  
...  
Keyword(s):  
Electrochemical Impedance ◽  
Immersion Test ◽  
Molar Ratio ◽  
Test Evaluation ◽  
Degradation Rates ◽  
Polarization Test ◽  
Micro Arc Oxidation ◽  
High Roughness ◽  
Zn Alloys ◽  
Better Than

Recent studies have indicated a great demand to optimize the biocompatibility properties of pure Zn as an implant material. For this purpose, CaZn2(PO4)2·2H2O (CaZnP) was prepared using hydrothermal treatment (HT) combined with micro-arc oxidation (MAO) on pure Zn substrate to generate biodegradable implants. The polarization test and electrochemical impedance spectroscopy indicated that the MAO1−HT coating could modulate the corrosion behavior of MAO1 by filling the crevice between the coating and the substrate. Immersion test evaluation revealed that the osteogenic properties of MAO1−HT coating were better than that of pure Zn substrate, as evidenced by the molar ratio of Ca and P, which increased after soaking in simulated body fluid (SBF) for up to 10 days. In addition, L-929 cells cultured in the 100%, 50%, and 25% extracts of MAO1−HT coated samples exhibited excellent cytocompatibility. Meanwhile, cell adhesion was promoted on the surface with high roughness generated during MAO and HT processes. In summary, the calcified coatings improved biocompatibility and adjusted the degradation rates of pure Zn, broadening the application of Zn alloys.

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