Corrosion Properties of Cold Spray Zn-25Al Coating in Marine Environment

2011 ◽  
Vol 148-149 ◽  
pp. 345-348
Author(s):  
Qing Jun Zhu ◽  
Kai Wang
Keyword(s):  
Cold Spray ◽  
Corrosion Potential ◽  
Electrochemical Impedance ◽  
Impedance Spectrum ◽  
Electrochemical Impedance Spectrum ◽  
Natural Seawater ◽  
Corrosion Properties ◽  
Dissolution Zone ◽  
Polarization Test ◽  
Protection Potential

Zn-25Al coatings were prepared by cold spray on mild carbon steel Q235. The coatings were studied by potentiodynamic polarization test, corrosion potentials and electrochemical impedance spectrum in natural seawater. The results show that the Ecorr of Zn-25Al coating is -1.01V (SCE) and the Ecorr of Q235 is -0.65V (SCE) at the beginning of the immersion. Self-corrosion potential of Zn-25Al coating is lower than that of Q235. The coatings turn to activity anodic dissolution zone when the potential reaches -1.05V. The coatings changes to passivation zone after the potential reaches -1.01V and the current intensities increase slightly with the potential increasing quickly. Zn-25Al coatings can provide lower protection potential and promising current to protect Q235 from corrosion.

Corrosion Properties of Arc Spray Zn-25Al and Zn-50Al Coating in Marine Environment

2011 ◽  
Vol 239-242 ◽  
pp. 1215-1218
Author(s):  
Qing Jun Zhu ◽  
Kai Wang
Keyword(s):  
Electrochemical Impedance ◽  
Impedance Spectrum ◽  
Electrochemical Impedance Spectrum ◽  
Natural Seawater ◽  
Corrosion Properties ◽  
Arc Spray ◽  
Seawater Corrosion ◽  
Capacitive Loop ◽  
Corrosion Behaviors ◽  
Protection Potential

Zn-25Al and Zn-50Al coatings were prepared by arc spray in mild carbon steel Q235. The corrosion behaviors of these coatings were studied by potentiodynamic polarization test in natural seawater, corrosion potentials and electrochemical impedance spectrum. The results show that the Ecorr of Zn-25Alcoating is -1.025V (SCE) and the Ecorr of Zn-50Al coating is -0.997V (SCE) at the beginning of the immersion. The Ecorr of the Zn-50Al coating is not stable as the Zn-25Al coating. Self-corrosion potential of Zn-25Al coating is lower than Zn-50Al coating. Zn-25Al can provide lower protection potential and promising current to protect the substrate from corrosion than Zn-50Al. The EIS of these two coatings reveal single capacitive loop. The anti-corrosion properties of Zn-25Al coatings are better than that of Zn-50Al coatings.

Corrosion-Deformation Interactions (CDI)of AA2024-T3 in Chloride Media

2011 ◽  
Vol 284-286 ◽  
pp. 2094-2101
Author(s):  
Si Xian Rao ◽  
Li Bing Zhang ◽  
Wei Wei ◽  
Zi Wei Pan
Keyword(s):  
Aqueous Solution ◽  
Strain Rate ◽  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Electrochemical Techniques ◽  
Impedance Spectrum ◽  
Electrochemical Impedance Spectrum ◽  
Breakdown Potential ◽  
Protection Potential ◽  
Low Strain Rate

Effects of CDI on corrosion behavior of AA2024-T3 in 3% NaCl aqueous solution are investigated through electrochemical techniques. the results show that CDI could lead to negative shift of free potential, breakdown potential and protection potential of AA2024-T3 and enhance the sensitivity of AA2024-T3 to pitting. The electrochemical impedance spectrum results show that Rp decreased significantly under applied stress and Rp can be taken as the indicator to evaluate the effect of CDI. Different strain rate could influence the effect of CDI on corrosion behavior and effect of CDI exhibit more significantly under low strain rate.

Electrochemical Impedance Characteristics of Sintered 7075 Aluminum Alloy Under Ssrt Condition

2013 ◽  
Vol 58 (2) ◽  
pp. 505-508 ◽  
Author(s):  
S. Sunada ◽  
N. Nunomura
Keyword(s):  
Aluminum Alloys ◽  
Complex Shape ◽  
Electrochemical Impedance ◽  
Ingot Metallurgy ◽  
View Point ◽  
Corrosion Properties ◽  
Electrochemical Tests ◽  
Impedance Characteristics ◽  
Polarization Test ◽  
Conventional Ingot

Powder metallurgy (P/M) process has the advantage of better formability to fabricate complex shape products without machining and welding. And recently this P/M process has been applied to the production of aluminum alloys. The P/M aluminum alloys thus produced also have received considerable interest because of their fine and homogeneous structure. Many papers have been published on the mechanical properties of the aluminum alloys produced by P/M process while there have been few on their corrosion properties from the view point of electrochemistry. In this experiment, therefore, two kinds of 7075 aluminum alloys prepared by the conventional ingot metallurgy (I/M) process and P/M process were used, I/M material is commercially available. and their corrosion behavior were investigated through the electrochemical tests such as potentiodynamic polarization test, slow rate strain tensile (SSRT) test and electrochemical impedance spectroscopy (EIS) measurement under SSRT test in the corrosion solution and the deionized water.

scholarly journals Study on the Synthesize, Characterization, and Conductive Performance of Nickelzircomolybdnum Heteropoly Acid Salt with Keggin Structure

2019 ◽  
Vol 2019 ◽  
pp. 1-4
Author(s):  
Zhihong Zhang ◽  
Baoying Wang ◽  
Yijing Zhang ◽  
Gehong Zhang ◽  
Yujing Wang
Keyword(s):  
Conduction Mechanism ◽  
Heteropoly Acid ◽  
Electrochemical Impedance ◽  
Impedance Spectrum ◽  
Heteropoly Compound ◽  
Electrochemical Impedance Spectrum ◽  
Acid Salt ◽  
X Ray Diffraction ◽  
Protonic Conduction ◽  
X Ray

A novel heteropoly acid salt, Na6[Ni(Mo11ZrO39)]·20H2O, has been synthesized by the means of acidification and adding the reactants into the solution step by step. The heteropoly compound was characterized by elemental analysis, TGA/DSC, infrared spectrum, ultraviolet spectrum, X-ray diffraction, and SEM. Its protonic conduction was measured by the means of the electrochemical impedance spectrum. The results showed that it belongs to the Keggin type, and its conductivity value was 1.23 × 10–2 S/cm at 23°C when the relative humidity was 60%, and the conductivity enhanced with the elevated temperature. Its proton conduction mechanism was in accordance with vehicle mechanism, and the activation energy was 27.82 kJ/mol.

Fe-Doped UiO-66 Combined with ZnIn2S4 for Adsorption and Degradation of RhB Under Visible Light

NANO ◽  
2020 ◽  
Vol 15 (07) ◽  
pp. 2050089
Author(s):  
Litong Niu ◽  
Shaoping Hu ◽  
Yali Ma ◽  
Mingming Wang ◽  
Bolin Lv ◽  
...  
Keyword(s):  
Visible Light ◽  
Electrochemical Impedance ◽  
Diffuse Reflectance Spectroscopy ◽  
Photogenerated Electron ◽  
Impedance Spectrum ◽  
Solvothermal Reaction ◽  
Electrochemical Impedance Spectrum ◽  
X Ray Diffraction ◽  
One Pot ◽  
Ft Ir

Novel ZnIn2S4/FeUiO-66 (ZFeU) photocatalyst with different proportion of FeUiO-66 has been successfully prepared by a facile one-pot solvothermal reaction. The as-synthesized nanocomposites have been thoroughly characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform-infrared spectroscopy (FT-IR), UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS), Brunauer–Emmett–Teller (BET) characterization, photoluminescence (PL) analysis and electrochemical impedance spectrum (EIS). The photocatalytic performance of ZFeU nanocomposites for the photodegradation of RhB under visible light irradiation was better than that of ZnIn2S4 and FeUiO-66 alone. The experiment results showed the 20% ZFeU nanocomposites had the best photocatalytic properties. At the same time, a probable mechanism was discussed and it was believed that introduction of FeUiO-66 on ZnIn2S4 would minimize the recombination of photogenerated electron-hole pairs, leading to the enhancement of the photocatalytic activity.

EIS Study of Corrosion Behavior of Hot-Dip Galvanized Steel in 5% NaCl Aqueous Solution

2011 ◽  
Vol 335-336 ◽  
pp. 779-782
Author(s):  
Shi Quan He ◽  
Hui Zhong
Keyword(s):  
Aqueous Solution ◽  
Equivalent Circuit ◽  
Corrosion Behavior ◽  
Immersion Time ◽  
Electrochemical Impedance ◽  
Corrosion Behaviour ◽  
Impedance Spectrum ◽  
Corrosion Products ◽  
Galvanized Steel ◽  
Electrochemical Impedance Spectrum

Corrosion behaviour of hot-dip galvanized steel in 5% NaCl aqueous solution was studied by electrochemical impedance spectrum (EIS) technique. The results revealed that corrosion behaviour of hot-dip galvanized steel has a great relationship with immersion time. With the increase of immersion time, corrosion products are constantly changing, and the impedance of corrosion products are different. Parameters fitted by equivalent circuit show that the impedance of corrosion products increased at first, then decreased.

Quantitative Rapid Analysis Method for Ofloxacin in Raw Milk Based on Molecule-Specific Recognition and Electrochemical Impedance Spectrum

2017 ◽  
Vol 60 (5) ◽  
pp. 1439-1443 ◽  
Author(s):  
Guohua Hui ◽  
Yibin Ying
Keyword(s):  
Quantitative Analysis ◽  
Electrochemical Impedance ◽  
Impedance Spectrum ◽  
Raw Milk ◽  
Rapid Analysis ◽  
Electrochemical Impedance Spectrum ◽  
Analysis Method ◽  
Eigen Values ◽  
Sodium Tetraphenylboron ◽  
Association Complex

Abstract. A quantitative rapid analysis method for ofloxacin detection in raw milk using molecule-specific recognition and an electrochemical impedance spectrum (EIS) technique was investigated in this study. An association complex (AC) formed by a combination of ofloxacin and sodium tetraphenylboron (ST) was used as the active material for electrochemical analysis. A carbon screen-printed electrode (CSE) was modified with the AC to form an electrochemical active membrane for ofloxacin detection. EIS data of pretreated raw milk samples were measured and analyzed with a non-linear bistable stochastic resonance (SR) model. Trace ofloxacin concentrations were characterized by SR output signal-to-noise ratio (SNR) eigen values. An ofloxacin quantitative analysis model was built based on SNR eigen values. Experimental results demonstrated that the proposed method presented good accuracy, repeatability, and recovery. It is a promising way for ofloxacin detection in raw milk. Keywords: Association complex, Electrochemical impedance spectrum, Ofloxacin, Quantitative analysis, Sodium tetraphenylboron.

scholarly journals Composition and Performance of Nanostructured Zirconium Titanium Conversion Coating on Aluminum-Magnesium Alloys

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Sheng-xue Yu ◽  
Rui-jun Zhang ◽  
Yong-fu Tang ◽  
Yan-ling Ma ◽  
Wen-chao Du
Keyword(s):  
Corrosion Resistance ◽  
Salt Solution ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Impedance Spectrum ◽  
Conversion Coating ◽  
Mg Alloy ◽  
Electrochemical Impedance Spectrum ◽  
X Ray ◽  
Titanium Salt

Nanostructured conversion coating of Al-Mg alloy was obtained via the surface treatment with zirconium titanium salt solution at 25°C for 10 min. The zirconium titanium salt solution is composed of tannic acid 1.00 g·L−1, K2ZrF60.75 g·L−1, NaF 1.25 g·L−1, MgSO41.0 g/L, and tetra-n-butyl titanate (TBT) 0.08 g·L−1. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectrum (FT-IR) were used to characterize the composition and structure of the obtained conversion coating. The morphology of the conversion coating was obtained by atomic force microscopy (AFM) and scanning electron microscopy (SEM). Results exhibit that the zirconium titanium salt conversion coating of Al-Mg alloy contains Ti, Zr, Al, F, O, Mg, C, Na, and so on. The conversion coating with nm level thickness is smooth, uniform, and compact. Corrosion resistance of conversion coating was evaluated in the 3.5 wt.% NaCl electrolyte through polarization curves and electrochemical impedance spectrum (EIS). Self-corrosion current density on the nanostructured conversion coating of Al-Mg alloy is9.7×10-8A·cm-2, which is only 2% of that on the untreated aluminum-magnesium alloy. This result indicates that the corrosion resistance of the conversion coating is improved markedly after chemical conversion treatment.

PREPARATION AND ELECTROCHEMICAL PERFORMANCE OF HYBRID MATERIALS CONTAINING HETEROPOLY ACID WITH DAWSON STRUCTURE AND POLYMERS

2012 ◽  
Vol 05 (04) ◽  
pp. 1250040 ◽  
Author(s):  
XIA TONG ◽  
WEN WU ◽  
SHENGMING ZHOU ◽  
QINGYIN WU ◽  
FAHE CAO ◽  
...  
Keyword(s):  
Hybrid Materials ◽  
Heteropoly Acid ◽  
Electrochemical Impedance ◽  
Impedance Spectrum ◽  
Xrd Analysis ◽  
Proton Conduction ◽  
Electrochemical Impedance Spectrum ◽  
Grotthuss Mechanism ◽  
Dawson Structure ◽  
Higher Temperature

Highly proton-conducting hybrid materials ( P2W17V /PEG and P2W17V/PEG/SiO2 ) were prepared by heptadecatungstovanadodiphosphoric heteropoly acid with Dawson structure ( P2W17V , 90 wt.%), polyethylene glycol (PEG, 10 wt.% and 5 wt.%) and silica gel ( SiO2 , 0 wt.% and 5 wt.%). The products were characterized by the infrared (IR) spectrum, X-ray powder diffraction (XRD) analysis and electrochemical impedance spectrum (EIS). The result reveals that their conductivity values are 1.02 × 10-2 and 2.58 × 10-2S ⋅ cm-1 at room temperature (26°C) and 75% relative humidity (RH), respectively. Their conductivities increase with higher temperature and these activation energies of proton conduction are 9.51 and 14.95 kJ⋅mol-1, which are lower than that of pure heteropoly acid (32.23 kJ⋅mol-1). These mechanisms of proton conduction for these two materials are Grotthuss mechanism.

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