scholarly journals The Protection Role of Cysteine for Cu-5Zn-5Al-1Sn Alloy Corrosion in 3.5 wt.% NaCl Solution

2019 ◽  
Vol 9 (18) ◽  
pp. 3896 ◽  
Author(s):  
Kebede W. Shinato ◽  
Feifei Huang ◽  
Yanpeng Xue ◽  
Lei Wen ◽  
Ying Jin

In this work, the corrosion mechanism of a Cu-5Zn-5Al-1Sn alloy was examined in a 3.5 wt.% NaCl solution. At the same time, the effect of a cysteine inhibitor was also investigated through a multi-analytical approach. Electrochemical results suggested that inhibition efficiency increased with the increase of cysteine concentration. From potentiodynamic polarization (PD) analysis, a decrease in corrosion current and corrosion potential shift toward a more negative direction was observed. The potential difference between the blank and inhibited surface was found to be 46 mV, which is less than 85 mV, revealing a mixed type inhibition effect of cysteine for the Cu-5Zn-5Al-1Sn alloy. The inhibition mechanism of cysteine (Cys) and the effect of alloying elements were investigated by fitting experimental impedance data according to a projected equivalent circuit for the alloy/electrolyte interface. A Langmuir adsorption isotherm was proposed to explain the inhibition phenomenon of cysteine on the Cu-5Zn-5Al-1Sn alloy surface. Surface morphology observation confirmed that the Cu-5Zn-5Al-1Sn alloy was damaged in 3.5 wt.% NaCl solution and could be inhibited by using the cysteine inhibitor. The impact of alloying elements on the corrosion mechanism was further examined by surface analysis techniques such as X-Ray photoelectron spectroscopy (XPS)/Auger spectra, the results of which indicated that the corrosion inhibition was realized by the adsorption of the inhibitor molecules at the alloy/solution interface.

Materials ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2069 ◽  
Author(s):  
Jian Ding ◽  
Xin Liu ◽  
Yujiang Wang ◽  
Wei Huang ◽  
Bo Wang ◽  
...  

The effect of Sn addition on the microstructure and corrosion behavior of extruded Mg–5Zn–4Al–xSn (0, 0.5, 1, 2, and 3 wt %) alloys was investigated by optical microscopy (OM), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), electrochemical measurements, and immersion tests. Microstructural results showed that the average grain size decreased to some degree and the amount of precipitates increased with the increasing amount of Sn. The extruded Mg–5Zn–4Al–xSn alloy mainly consisted of α-Mg, Mg32(Al,Zn)49, and Mg2Sn phases as the content of Sn was above 1 wt %. Electrochemical measurements indicated that the extruded Mg–5Zn–4Al–1Sn (ZAT541) alloy presented the best corrosion performances, with corrosion potential (Ecorr) and corrosion current density (Icorr) values of −1.3309 V and 6.707 × 10−6 A·cm−2, respectively. Furthermore, the corrosion mechanism of Sn is discussed in detail.


2007 ◽  
Vol 22 (9) ◽  
pp. 2573-2581 ◽  
Author(s):  
Udit Surya Mohanty ◽  
Kwang-Lung Lin

The electrochemical corrosion behavior of Sn–XAg–0.5Cu alloys in 3.5% NaCl solution was examined using potentiodynamic polarization techniques. The Ag content in the alloy was varied from 1 to 4 wt%. The polarization curves obtained for the alloys show an active–passive transition followed by a transpassive region. Sn–XAg–0.5Cu alloys with higher Ag content (>2 wt%) show a strong tendency toward passivation. The passivation behavior has been ascribed to the presence of both SnO and SnO2on the anode surface. Increase in Ag content from 1 to 4 wt% results in a decrease in the corrosion-current density (Icorr) and linear polarization resistance (LPR) of the alloy. Nevertheless, the corrosion potential (Ecorr) shifts toward negative values, and a decrease in corrosion rate is observed. The presence of Cl−ion initiates pitting and is responsible for the rupture of the passive layer at a certain breakdown potential. The breakdown potential (EBR) decreases and shifts toward more noble values with increase in Ag content in the alloy. Surface analyses by x-ray photoelectron spectroscopy (XPS) and Auger depth profile studies confirmed the formation of both Sn(II) and Sn(IV) oxides in the passive layer.


2014 ◽  
Vol 575 ◽  
pp. 210-213
Author(s):  
Elsadig Mahdi ◽  
E. Eltai

Aluminium alloy 6061 T6 circular specimens were joined using TIG welding method. AlMg5 was used as filler. The corrosion behavior of welded and un-welded AA 6061 T6 was investigated using potentiodynamic and open circuit potential (OCP) measurements. Specimens were immersed in 3.5 (wt %) NaCl solution. Different zones with different corrosion properties were created as a result of the welding process. Results reveals that sever pitting corrosion has taken place on the heat affected zone (HAZ); the corrosion current of HAZ was increased. The measured potential of HAZ was more negative and largely fluctuated comparing to base metal (BM).


Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 837 ◽  
Author(s):  
Weihang Li ◽  
Bojun Song ◽  
Shirui Zhang ◽  
Fan Zhang ◽  
Chang Liu ◽  
...  

In this paper, the graphene oxide loaded with nano titanium dioxide (TiO2–GO) was synthesized through 3-isocyanatopropyltrimethoxysilane (IPTMS) and characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction analysis (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and dispersion test. The results illustrated our modification was successful and TiO2–GO was transferred from hydrophilic to hydrophobic. That greatly enhanced the dispersity of TiO2–GO in epoxy through the observation of the coating morphology test. Moreover, the impact of TiO2–GO on anti-corrosion property in epoxy was investigated by Electrochemical Impedance Spectroscopy (EIS). Comparing to pristine particles including GO and TiO2, TiO2–GO could more significantly improve the resistance of corrosion with the help of IPTMS. Furthermore, the anti-corrosion mechanism of TiO2–GO in epoxy was tentatively proposed and discussed.


CORROSION ◽  
10.5006/2408 ◽  
2017 ◽  
Vol 73 (9) ◽  
pp. 1107-1118 ◽  
Author(s):  
Yuantao Zhao ◽  
Lianbo Wang ◽  
Zhenbo Qin ◽  
Chengxi Wang ◽  
Zhou Xu ◽  
...  

The influences of co-deposited Ti particles on corrosion behavior of electrodeposited Ni-Ti coatings were investigated. The co-deposited Ti particles caused the refined crystallite size and random-oriented texture of Ni-Ti coating. In 3.5 wt% sodium chloride (NaCl) solution, the buried Ti particles in Ni matrix blocked the corrosion path and rapid intercrystalline corrosion. The inert TiO2 could form on the exposed Ti particles and hinder localized corrosion. In 10 wt% sodium hydroxide (NaOH) solution, Ni matrix crystallites, refined by co-deposited Ti particles, contributed to formation of the passive Ni(OH)2 film. The corrosion current of Ni-Ti coating decreased by about one order of magnitude in both solutions with respect to pure Ni coating, demonstrating the co-deposited Ti particles greatly improved the corrosion resistance of Ni-Ti composite coatings. Finally, a corrosion mechanism was built to explain the co-deposited Ti particles improved corrosion resistance of the Ni-Ti composite coatings.


2009 ◽  
Vol 46 (2) ◽  
pp. 97-114 ◽  
Author(s):  
Mile Djurdjevic ◽  
Jelena Pavlovic ◽  
Glenn Byczynski

2021 ◽  
pp. 002199832199945
Author(s):  
Jong H Eun ◽  
Bo K Choi ◽  
Sun M Sung ◽  
Min S Kim ◽  
Joon S Lee

In this study, carbon/epoxy composites were manufactured by coating with a polyamide at different weight percentages (5 wt.%, 10 wt.%, 15 wt.%, and 20 wt.%) to improve their impact resistance and fracture toughness. The chemical reaction between the polyamide and epoxy resin were examined by fourier transform infrared spectroscopy, differential scanning calorimetry and X-ray photoelectron spectroscopy. The mechanical properties and fracture toughness of the carbon/epoxy composites were analyzed. The mechanical properties of the carbon/epoxy composites, such as transverse flexural tests, longitudinal flexural tests, and impact tests, were investigated. After the impact tests, an ultrasonic C-scan was performed to reveal the internal damage area. The interlaminar fracture toughness of the carbon/epoxy composites was measured using a mode I test. The critical energy release rates were increased by 77% compared to the virgin carbon/epoxy composites. The surface morphology of the fractured surface was observed. The toughening mechanism of the carbon/epoxy composites was suggested based on the confirmed experimental data.


Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1581
Author(s):  
Rafał Babilas ◽  
Monika Spilka ◽  
Katarzyna Młynarek ◽  
Wojciech Łoński ◽  
Dariusz Łukowiec ◽  
...  

The effect of iron and yttrium additions on glass forming ability and corrosion resistance of Al88Y8-xFe4+x (x = 0, 1, 2 at.%) alloys in the form of ingots and melt-spun ribbons was investigated. The crystalline multiphase structure of ingots and amorphous-crystalline structure of ribbons were examined by a number of analytical techniques including X-ray diffraction, Mössbauer spectroscopy, and transmission electron microscopy. It was confirmed that the higher Fe additions contributed to formation of amorphous structures. The impact of chemical composition and structure of alloys on their corrosion resistance was characterized by electrochemical tests in 3.5% NaCl solution at 25 °C. The identification of the mechanism of chemical reactions taking place during polarization test along with the morphology and internal structure of the surface oxide films generated was performed. It was revealed that the best corrosion resistance was achieved for the Al88Y7Fe5 alloy in the form of ribbon, which exhibited the lowest corrosion current density (jcorr = 0.09 μA/cm2) and the highest polarization resistance (Rp = 96.7 kΩ∙cm2).


Author(s):  
Władysław Janusz ◽  
Ewa Skwarek

AbstractThe aim of the study was the basic incidence on the phenomenon of adsorption that occurs at the hydroxyapatite/malic acid interface, leading to a change in the surface properties of hydroxyapatite, Analytical methods used in the research: X-ray diffraction (XRD) as well as by the, adsorption–desorption of nitrogen (ASAP), potentiometric titration. The specific adsorption of malic acid ions at the hydroxyapatite interface was investigated by means of the radioisotope method. The zeta potential of hydroxyapatite dispersions was determined by electrophoresis with Zetasizer Nano ZS90 by Malvern. The particle sizes of hydroxyapatite samples were analyzed using Masteriszer 2000 Malvern. Studies on the kinetics of malic acid on hydroxyapatite from a solution with an initial concentration of 1 mmol/dm3 have shown that the adsorption process is initially fast, followed by a slow adsorption step. An increase in the pH of the solution causes a decrease in the malic acid adsorption as a result of competition with hydroxyl ions. The presence of adsorbed malic acid was confirmed by the FTIR measurements. The effect of malic acid adsorption on the zeta potential and particle size distribution of hydroxyapatite in the NaCl solution was investigated.


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