scholarly journals The Electrochemical Stability in NaCl Solution of Nanotubes and Nanochannels Elaborated on a New Ti-20Zr-5Ta-2Ag Alloy

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Claudiu Constantin Manole ◽  
Cristian Pirvu ◽  
Andrei Bogdan Stoian ◽  
Jose M. Calderon Moreno ◽  
Doina Stanciu ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Corrosion Resistance ◽  
Electrochemical Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Contact Angles ◽  
Electrochemical Stability ◽  
Tubular Structures ◽  
Nacl Solution ◽  
Nanostructured Surfaces ◽  
Hydrophilic Character

Nanotubular and nanochannels structures were fabricated via anodizing on a new alloy Ti-20Zr-8Ta-2Ag. A continuous coating of connected tubes/channels can be observed in the SEM micrographs forming tubular structures with diameters in hundreds of nm, as well as smaller tubes, with diameters in tens of nm. In the case of nanochannels structure, the diameters are smaller and wall thicknesses significantly thinner than in nanotubes. Wettability measurements indicate a decrease of contact angles in both cases of nanotubes and nanochannels, but the increase of hydrophilic character is more significant in the case of nanochannels. The Tafel procedure and electrochemical impedance spectroscopy tests performed in NaCl 0.9% solution indicate a better stability for the nanostructured surfaces compared to untreated alloy, the surface with nanochannels offering higher corrosion resistance. Spectral UV-VIS determination has confirmed Ag metallic presence, opening the door for applications not only in tissue engineering but for water splitting and the photoreduction of CO2as well.

scholarly journals Effects of NiSO4 Concentration on the Coloring Performance and Corrosion Resistance of the Colored Film on 304 Stainless Steel

Coatings ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 598
Author(s):  
Wenwei Li ◽  
Jun-e Qu ◽  
Zhiyong Cao ◽  
Hairen Wang
Keyword(s):  
Stainless Steel ◽  
Wear Resistance ◽  
Corrosion Resistance ◽  
Electrochemical Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Negative Impact ◽  
304 Stainless Steel ◽  
Nacl Solution ◽  
Time Curve ◽  
Steel Surfaces

The colored films were successfully prepared on the 304 stainless steel surfaces in coloring solutions with different NiSO4 contents. The purpose of this study was to investigate the effects of NiSO4 in the coloring solution on the coloring performance of 304 stainless steel and corrosion resistance of the obtained colored film in NaCl solution. The coloring rate was determined from coloring potential-time curve, and the protection properties of the color films in a 3.5% NaCl solution were characterized by potentiodynamic polarization scan, electrochemical impedance spectroscopy, and wear resistance test. The results showed that adding NiSO4 could accelerate the coloring process but brought about a negative impact on the surface’s corrosion resistance.

Effect of KI on the Corrosion Resistance of Ni-P Electroless Plating Coating

2014 ◽  
Vol 633-634 ◽  
pp. 817-820
Author(s):  
Ping Liang ◽  
Yun Xia Zhang ◽  
Yan Hua Shi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Corrosion Resistance ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Phosphorus Content ◽  
Electrochemical Impedance ◽  
Nacl Solution ◽  
Electroless Coating ◽  
Scanning Electron

To improve the corrosion resistance of Ni-P electroless coating, the KI was added in the electroless solution. The surface micrograph was observed using scanning electron microscopy (SEM), and the corrosion resistance of Ni-P coatings in 3.5%NaCl solution was examined by polarization curves and electrochemical impedance spectroscopy (EIS). The experimental results showed that KI reduced the amount of defects and the size of crystal grain of Ni-P coating, and the surface of Ni-P coating became more homogenous, smoother and compact by KI. In addition, the phosphorus content of Ni-P coating was increased by KI. These factors increased the ability to corrosion protection of Ni-P coating.

Corrosion Resistance of Ultrafine-Grained Pure Cu

2014 ◽  
Vol 912-914 ◽  
pp. 69-72
Author(s):  
D.R. Fang ◽  
L.W. Quan ◽  
J. Yang
Keyword(s):  
Corrosion Resistance ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Corrosion Rate ◽  
Electrochemical Impedance ◽  
Coarse Grained ◽  
Nacl Solution ◽  
Angular Pressing ◽  
Ultrafine Grained ◽  
Pure Cu

Pure Cu samples were subjected to equal channel angular pressing (ECAP), and the corrosion resistance of the samples was investigated by potentiodynamic polarization measurements and electrochemical impedance spectroscopy measurements in 3.5% NaCl solution. The results show that the corrosion rate of the ultrafine-grained Cu decreases, in comparison with the coarse-grained Cu.

Electrochemical Behavior of Corrosion Resistance Alloys

2011 ◽  
Vol 418-420 ◽  
pp. 1097-1101 ◽  
Author(s):  
Tao Zhang ◽  
Hong Yang Jing ◽  
Yong Dian Han ◽  
Lian Yong Xu
Keyword(s):  
Corrosion Resistance ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Ambient Temperature ◽  
Electrochemical Behavior ◽  
Electrochemical Impedance ◽  
Inconel 625 ◽  
Nacl Solution ◽  
Nyquist Plots ◽  
Potentiodynamic Polarisation

The electrochemical behavior of corrosion resistance alloys (316L SS, 2205 DSS and Inconel 625) was carried out at ambient temperature in 3.5% NaCl solution using potentiodynamic polarisation and electrochemical impedance spectroscopy (EIS) techniques. Some significant characterization parameters such as Ecorr, Eb, Icorrand △E in polarisation curves were analyzed and compared to reveal the corrosion resistance of corrosion resistance alloys. The ZsimpWin software was utilized to discuss the Nyquist plots of various corrosion resistance alloys. The result shows that the corrosion resistance of the corrosion resistance alloys in 3.5% NaCl solution at ambient temperature follows the sequence: Inconel 625> 2205 DSS > 316L SS.

Electrochemical Impedance Spectroscopy (EIS) Study of Nano-Composite Polyurea Coating under the Wet-Dry Cyclic Conditions

2014 ◽  
Vol 789 ◽  
pp. 495-500
Author(s):  
Bing Ying Wang ◽  
Qing Hao Shi ◽  
Wen Long Zhang
Keyword(s):  
Corrosion Resistance ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Composite Coating ◽  
Electrochemical Impedance ◽  
Protective Action ◽  
Experimental Result ◽  
Resistance Property ◽  
Corrosion Resistance Property ◽  
Mass Fractions

The polyurea was modified by adding different amounts of nanometer ZnO. The corrosion behavior of polyurea/primer composite coating system in wet-dry cyclic environment of 3.5% NaCl solution was studied by using the Electrochemical Impedance Spectroscopy (EIS) measurement and adhesion test technology. The experimental result showed that, different mass fractions of nanometer ZnO had different influences on the corrosion resistance property of coating. When the mass fraction of nanometer ZnO was 5%, the composite coating had the largest protective action. The corrosion resistance property of nanometer ZnO can be improved by increasing the density of polyurea coating, however, the corrosion resistance property of polyurea coating will be weakened in case of exceeding the critical adding amount.

scholarly journals Assessment of nickel titanium and beta titanium corrosion resistance behavior in fluoride and chloride environments

2013 ◽  
Vol 83 (5) ◽  
pp. 864-869 ◽  
Author(s):  
Elisa J. Kassab ◽  
José Ponciano Gomes
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Fluoride Concentration ◽  
Nickel Titanium ◽  
Localized Corrosion ◽  
General Corrosion ◽  
Nacl Solution ◽  
Galvanic Coupling ◽  
Beta Titanium

ABSTRACT Objective: To assess the influence of fluoride concentration on the corrosion behavior of nickel titanium (NiTi) superelastic wire and to compare the corrosion resistance of NiTi with that of beta titanium alloy in physiological solution with and without addition of fluoride. Materials and Methods: NiTi corrosion resistance was investigated through electrochemical impedance spectroscopy and anodic polarization in sodium chloride (NaCl 0.15 M) with and without addition of 0.02 M sodium fluoride (NaF), and the results were compared with those associated with beta titanium. The influence of fluoride concentration on NiTi corrosion behavior was assessed in NaCl (0.15 M) with and without 0.02, 0.04, 0.05, 0.07, and 0.12 M NaF solution. Galvanic corrosion between NiTi and beta titanium were investigated. All samples were characterized by scanning electron microscopy. Results: Polarization resistance decreased when NaF concentration was increased, and, depending on NaF concentration, NiTi can suffer localized or generalized corrosion. In NaCl solution with 0.02 M NaF, NiTi suffer localized corrosion, while beta titanium alloys remained passive. Current values near zero were observed by galvanic coupling of NiTi and beta titanium. Conclusions: There is a decrease in NiTi corrosion resistance in the presence of fluoride. The corrosion behavior of NiTi alloy depends on fluoride concentration. When 0.02 and 0.04 M of NaF were added to the NaCl solution, NiTi presented localized corrosion. When NaF concentration increased to 0.05, 0.07, and 0.12 M, the alloy presented general corrosion. NiTi corrosion resistance behavior is lower than that of beta titanium. Galvanic coupling of these alloys does not increase corrosion rates.

Corrosion Resistance of Nd-Fe-B Magnets Coated with Polypyrrole Films

2006 ◽  
Vol 530-531 ◽  
pp. 111-116
Author(s):  
M.C.E. Bandeira ◽  
F.D. Prochnow ◽  
Isolda Costa ◽  
César V. Franco
Keyword(s):  
Corrosion Resistance ◽  
Electrochemical Impedance ◽  
Nacl Solution ◽  
Corrosion Performance ◽  
Low Frequencies ◽  
Polypyrrole Films ◽  
Phosphate Ions ◽  
Polypyrrole Film ◽  
Corrosive Environments ◽  
Magnet Surface

Nd-Fe-B magnets present outstanding magnetic properties. However, due to their low corrosion resistance, their applications are limited to non-corrosive environments. Nowadays, significant efforts are underway to increase the corrosion resistance of these materials, through the use of coatings. Herein are presented the results of a study on the corrosion resistance of Nd-Fe-B magnets coated with polypyrrole (PPY). The electrochemical behavior of coated and uncoated magnets has been studied by Electrochemical Impedance spectroscopy (EIS) in synthetic saliva. The results were compared to previous investigations, which were carried out under similar conditions, in Na2SO4 and NaCl solutions. In sulphate solution, the corrosion resistance of the PPY-coated magnet was 3 times larger (1600 .cm2) than that of uncoated magnet (500 .cm2). In NaCl solution, however, the corrosion resistance of coated and uncoated magnets were very similar (250 .cm2). In synthetic saliva, both the uncoated and coated magnets presented good corrosion performance (1940 .cm2). Such behavior can be attributed to the phosphate ions in saliva, which play a role as corrosion inhibitor, producing phosphating, at least partially, of the magnet surface. The PPY-coated magnets presented a strong diffusional control from moderate to low frequencies, caused by the polypyrrole film. The thicker PPY film increased the corrosion resistance of the magnet in synthetic saliva.

The effect of electroplating current density on microstructure, corrosion, and wear behavior of Ni–P–W–TiO2 coating

2021 ◽  
Vol 112 (6) ◽  
pp. 474-485
Author(s):  
Sajjad Sadeghi ◽  
Hadi Ebrahimifar
Keyword(s):  
Wear Resistance ◽  
Corrosion Resistance ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Current Density ◽  
Potentiodynamic Polarization ◽  
Electrochemical Impedance ◽  
Wear Behavior ◽  
Micro Hardness ◽  
Aisi 304L

Abstract The use of ceramic particles in the matrix of alloy coatings during the electroplating process has received considerable attention. These particles can create properties such as high corrosion resistance, insolubility, high-temperature stability, strong hardness, and self-lubrication capability. Herein, an Ni–P–W–TiO2 coating was deposited on an AISI 304L steel substrate using the electroplating method. Electroplating was performed at current densities of 10, 15, 20, and 25 mA · cm–2, and the effect of current density on microstructure, corrosion behavior, and wear behavior was investigated. The coatings were characterized by means of scanning electron microscopy. To investigate corrosion resistance, potentiodynamic polarization and electrochemical impedance spectroscopy tests were performed in a 3.5% NaCl aqueous solution. A pin-on-disk test was conducted to test the wear resistance of uncoated and coated samples. Sample micro-hardness was also measured by Vickers hardness testing. Examination of the microstructure revealed that the best coating was produced at a current density of 20 mA · cm–2. The results of potentiodynamic polarization and electrochemical impedance spectroscopy tests were consistent with microscopic images. The coating created at the current density of 20 mA · cm–2 had the highest corrosion resistance compared to other coated and non-coated samples. Furthermore, the results of the wear test showed that increasing the current density of the electroplating path up to 20 mA · cm–2 enhances micro-hardness and wear resistance.

Corrosion characteristics of plasma spray, arc spray, high velocity oxygen fuel, and diamond jet coated 30MnB5 boron alloyed steel in 3.5 wt.% NaCl solution

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Bekir Güney ◽  
Yusuf Dilay ◽  
Moses M. Solomon ◽  
Hüsnü Gerengi ◽  
Adem Özkan ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Plasma Spray ◽  
High Velocity ◽  
Electrochemical Impedance ◽  
Iron Carbide ◽  
Alloyed Steel ◽  
Coated Sample ◽  
Nacl Solution ◽  
Arc Spray ◽  
Coated Surfaces

Abstract 30MnB5 boron alloyed steel surface is coated using different coating techniques, namely 60(Ni-15Cr-4.4Si-3.5Fe-3.2B 0.7C)-40(WC 12Co) metallic powder plasma spray, Fe-28Cr-5C-1Mn alloy wire arc spray, WC-10Co-4Cr (thick) powder high velocity oxy-fuel (HVOF), and WC-10Co-4Cr (fine) diamond jet HVOF. The microstructure of the crude steel sample consists of ferrite and pearlite matrices and iron carbide structures. The intermediate binders are well bonded to the substrate for all coated surfaces. The arc spray coated surface shows the formation of lamellae. The cross-section of HVOF and diamond jet HVOF coated surfaces indicates the formation of WC, W2C Cr, and W parent matrix carbide structures. The corrosion characteristic of the coated steel has been investigated in 3.5 wt.% NaCl solution using electrochemical impedance spectroscopy (EIS), scanning electron microscope (SEM), and energy dispersive X-ray spectroscopy (EDAX) techniques. The results reveal that the steel corroded in the medium despite the coatings. However, the extent of corrosion varies. HVOF coated sample demonstrated the highest corrosion resistance while arc spray coated sample exhibited the least. EDAX mapping reveals that the elements in the coatings corroded in the order of their standard electrode potential (SEP). Higher corrosion resistance of HVOF coated sample is linked to the low SEP of tungsten.

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