Effect of Zn content on corrosion behavior of Mg-Y-Zn alloys

The microstructure, corrosion behavior and electrochemical behavior of as-cast Mg-4Y-xZn (x=1,2,3,4 wt.%) are studied by SEM, weight loss and electrochemical tests. Mg12YZn (X), Mg3Y2Zn3 (W) and Mg24Y5 constitute the phase composition system of the alloy. When Zn content is 1 wt.%, all tests reveal that alloy has the optimal corrosion performance. The second phase in these alloys, due to their nobler nature than ?-Mg, exists as cathode during corrosion process, so that ?-Mg preferentially occurs corrosion to accelerate the formation of corrosion pits. After soaking in 3.5 wt.% NaCl solution for some time, the stability of the W phase changed, and gradually dissolved, which was finally removed by chromic acid used for removal of corrosion products. In addition, X phase can be used as an anode in the micro-galvanic cells formed with W phase to reduce the corrosion rate of ?-Mg and thus improve the corrosion performance of the alloy.

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Effect of YAl2 Particles on the Corrosion Behavior of Mg–Li Matrix Composite in NaCl Solution

Materials ◽

10.3390/ma12030549 ◽

2019 ◽

Vol 12 (3) ◽

pp. 549 ◽

Cited By ~ 4

Author(s):

Zihan Chen ◽

Chonggao Bao ◽

Guoqing Wu ◽

Yongxin Jian ◽

Li Zhang

Keyword(s):

Corrosion Resistance ◽

Intermetallic Compound ◽

Corrosion Behavior ◽

Matrix Composite ◽

Surface Film ◽

Interface Layer ◽

Corrosion Products ◽

Nacl Solution ◽

The Stability ◽

Main Factor

The strength of Mg–Li alloy is greatly improved by the composite strengthening of intermetallic compound YAl2 particles, but the low corrosion resistance of Mg–Li alloy is still the main factor that restricts the application of the alloy and its composites. In this paper, the effect of YAl2 particles on the corrosion behavior of Mg–Li alloy was systematically investigated. The results showed that the corrosion resistance of YAl2p/LA143 composite could be significantly improved, accounting for the formation of a transitional interface layer by adding YAl2 particles. The diffusion of yttrium and aluminum atoms from YAl2 particulates improved the stability of the surface film and enhanced the adhesion between the corrosion products and the substrate, which hindered further expansion of pitting.

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In-Situ Raman Characterization of Initial Corrosion Behavior of Copper in Neutral 3.5% (wt.) NaCl Solution

Materials ◽

10.3390/ma12132164 ◽

2019 ◽

Vol 12 (13) ◽

pp. 2164 ◽

Cited By ~ 4

Author(s):

Ming Liu ◽

Jun Li

Keyword(s):

Corrosion Behavior ◽

Cuprous Chloride ◽

Precipitation Reaction ◽

Nacl Solution ◽

In Situ Raman Spectroscopy ◽

Electrochemical Tests ◽

In Situ Raman ◽

Raman Characterization ◽

Over Time

In order to investigate the role of chloride ion in the corrosion film formation of copper and its evolution over time, the initial corrosion behavior of copper in neutral 3.5% (wt.) NaCl solution was characterized by in-situ Raman spectroscopy along with electrochemical tests. The results demonstrated that the cuprous chloride complexes, such as CuCl and CuCl 2 − were produced through electrode processes, while the cuprite, Cu 2 O seemed to be formed via the chemical precipitation reaction instead of a direct electrochemical transformation from the metal matrix or CuCl and it occurred rather slowly. At the open circuit potential, the chlorides were generated first in the initial 2 h and then they transformed to the oxides with the CuCl 2 − content in the interface increasing. The in-situ Raman characterization directly evidenced the previously reported mechanism of growth of oxide layers on copper surfaces in neutral Cl − media and clearly showed the formation of a corrosion product film and its evolution over time. The electrochemical tests corresponded to the results of in-situ Raman characterization well.

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The corrosion behavior of chromated AA2024 aluminum alloy in 3.5% NaCl solution

Anti-Corrosion Methods and Materials ◽

10.1108/acmm-01-2019-2070 ◽

2019 ◽

Vol 66 (6) ◽

pp. 879-887 ◽

Cited By ~ 5

Author(s):

Yong Zhou ◽

Pei Zhang ◽

Jinping Xiong ◽

Fuan Yan

Keyword(s):

Aluminum Alloy ◽

Grain Boundary ◽

Corrosion Behavior ◽

Electrochemical Measurement ◽

Nacl Solution ◽

Content Type ◽

Chromate Conversion Coating ◽

Chromate Coating ◽

Corrosion Mechanisms ◽

Corrosion Pits

Purpose A chromate conversion coating was prepared on the surface of bare AA2024 aluminum alloy by direct immersion in the chromating treatment bath, and the corrosion behavior of chromated AA2024 aluminum alloy in 3.5 per cent NaCl solution was studied by electrochemical measurement and microstructural observation. Design/methodology/approach According to the polarization curve test and the scanning electron microscope observation, the corrosion evolution of chromated AA2024 in 3.5 per cent NaCl solution was divided into the following three stages: coating failure, pitting corrosion and intergranular corrosion (IGC). Findings In the first stage, the chromate coating degraded gradually due to the combined action of chloride anions and water molecules, resulting in the complete exposure of AA2024 substrate to 3.5 per cent NaCl solution. Subsequently, in the second stage, chloride anions adsorbed at the sites of θ phase (Al2Cu) and S phase (Al2CuMg) on the AA2024 surface preferentially, and some corrosion pits initiated at the above two sites and propagated towards the deep of crystal grains. However, the propagation of a pit terminated when the pit front arrived at the adjacent grain boundary, where the initiation of IGC occurred. Originality/value Finally, in the third stage, the corrosion proceeded along the continuous grain boundary net and penetrated the internal of AA2024 substrate, resulting in the propagation of IGC. The related corrosion mechanisms for the bare and the chromated AA2024 were also discussed.

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Corrosion Behavior of Commercial Aluminum Alloy Processed by Equal Channel Angular Pressing

International Journal of Corrosion ◽

10.1155/2013/983261 ◽

2013 ◽

Vol 2013 ◽

pp. 1-11 ◽

Cited By ~ 16

Author(s):

Atef Korchef ◽

Abdelkrim Kahoul

Keyword(s):

Aluminum Alloy ◽

Equal Channel Angular Pressing ◽

Corrosion Behavior ◽

Volume Fraction ◽

Aluminum Matrix ◽

Electrochemical Tests ◽

Commercial Aluminum Alloy ◽

Enhanced Dissolution ◽

Galvanic Cells ◽

Angular Pressing

A commercial aluminum alloy was subjected to severe plastic deformation through equal channel angular pressing (ECAP). The alloy contains a low volume fraction ofα-AlFeSi located essentially at the grain boundaries. The corrosion behavior of the ECAP’ed alloy was investigated in NaCl solution using potentiodynamic polarization and immersion tests. The effects of scan rate and NaCl concentration on the alloy susceptibility to corrosion were also studied. The results obtained were compared with those of the nonpressed alloy. ECAP leads to an intensive grain refinement accompanied by an increased dislocation density. All electrochemical tests confirm that corrosion resistance of the alloy remarkably diminished with increasing the ECAP number of passes. This is presumably due to the breakdown of theα-AlFeSi after ECAP leading to higher number of galvanic cells and enhanced dissolution of the aluminum matrix.

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Study on Microstructure and Corrosion Behavior of Ag-Cu-Zn-Ni Alloys

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.311-313.2132 ◽

2011 ◽

Vol 311-313 ◽

pp. 2132-2137 ◽

Cited By ~ 1

Author(s):

Fu Xiang Huang ◽

Ping Yin ◽

Yong Hong Xu ◽

Ying Zhang

Keyword(s):

Corrosion Behavior ◽

Energy Dispersive Spectrum ◽

Second Phase ◽

X Ray Diffraction ◽

Silver Alloys ◽

X Ray ◽

Electrochemical Tests ◽

Ni Alloys ◽

Second Phases ◽

Electronic Microscope

Potentiodynamic electrochemical tests and surface analysis technics, such as scanning electronic microscope (SEM), energy dispersive spectrum (EDS) and X-ray diffraction analysis (XRD), were applied to investigate the microstructure and corrosion behavior of Ag-Cu-Zn-Ni alloys in Na2S solution. The results reveal that the α-Ag phase is the main matrix of the studied silver alloys. The second phase of Ag-4Cu-0.3Ni and Ag-3Cu-Zn-0.3Ni/Ag-6Cu-Zn-0.3Ni are respectively CuNi and CuNi(Zn) phases. The second phases of Ag-6Cu-Zn-0.3Ni are well-distributed, which leads to an improvement in the corrosion resistance in Na2S solution.

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Corrosion Behavior of Fe40Al Alloy with Additions of Ti, Ag, and Cr in Molten KCl +ZnCl2

International Journal of Corrosion ◽

10.1155/2012/146486 ◽

2012 ◽

Vol 2012 ◽

pp. 1-9 ◽

Cited By ~ 2

Author(s):

R. Ademar ◽

J. G. Gonzalez-Rodriguez ◽

J. Uruchurtu ◽

J. Porcayo-Calderon ◽

V. M. Salinas-Bravo ◽

...

Keyword(s):

Corrosion Rate ◽

Corrosion Behavior ◽

Electrochemical Impedance ◽

Electrochemical Techniques ◽

Intermetallic Alloy ◽

Corrosion Performance ◽

Linear Polarization Resistance ◽

Potentiodynamic Polarization Curves ◽

Eis Measurements ◽

The Stability

The effect of 2.5 at.% Cr, Ti, and Ag on the corrosion behavior of Fe40Al intermetallic alloy in KCl-ZnCl2(1 : 1 M) at 670°C has been evaluated by using electrochemical techniques. Techniques included potentiodynamic polarization curves, linear polarization resistance (LPR), and electrochemical impedance spectroscopy (EIS) measurements. Results have shown that additions of both Cr and Ti were beneficial to the alloy, since they decreased its corrosion rate, whereas additions of Ag was detrimental, since its additions increased the corrosion rate, although the alloy was passivated by adding Ag or Cr. The best corrosion performance was obtained with the addition of Cr, whereas the highest corrosion rate was obtained by adding Ag. This is explained in terms of the stability of the corrosion products formed film.

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Corrosion behavior of Ti/Al laminate composites as electrode of chlor-alkali electrolysis

Advanced Composites Letters ◽

10.1177/2633366x20920888 ◽

2020 ◽

Vol 29 ◽

pp. 2633366X2092088

Author(s):

Lixia Wang ◽

Limin Sun ◽

Yang Cao ◽

Jing Shen

Keyword(s):

Corrosion Behavior ◽

High Performance ◽

Electrochemical Impedance ◽

Intermetallic Phase ◽

Electricity Consumption ◽

Corrosion Current ◽

Electrode System ◽

Nacl Solution ◽

Electrochemical Tests ◽

Anode Electrode

High-performance electrodes can solve problems of high voltage and large electricity consumption existing in chlor-alkali industry. A Ti/Al laminate composite (named as Ti/Al-LC) with three-layered structure (Ti/Al3Ti/Ti) is prepared as a new type of anode electrode for chlor-alkali electrolysis. Scanning electron microscope observation shows that the Ti/Al-LC is composited of a thicker inner layer with thickness about 700 µm and two thinner outer layers with thickness about 300 µm. From the X-ray diffraction pattern, it is known that the outer layers consisted of α-Ti and β-Ti phases, while the inner layer consisted of Al3Ti intermetallic phase. A saturated sodium chloride (NaCl) solution at 70°C is purposely chosen as the corrosion electrolyte to analyze the corrosion behavior of Ti/Al-LC as anode electrode for chlor-alkali electrolysis. Electrochemical tests, including potentiodynamic polarization and electrochemical impedance spectroscopy measurements, on a three-electrode system indicate that the Ti/Al-LC has a low corrosion rate with corrosion current density of 1.94 µA cm−2 and stable surface passive film in saturated NaCl solution at 70°C.

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Effect of Sealing Treatments on the Corrosion Behavior of Micro-arc Oxidation Coating on Aluminum Alloy in Acid NaCl Solution

Journal of Inorganic Materials ◽

10.15541/jim20140582 ◽

2015 ◽

Vol 30 (6) ◽

pp. 627

Author(s):

YE Zuo-Yan ◽

LIU Dao-Xin ◽

LI Chong-Yang ◽

ZHANG Xiao-Hua ◽

ZANG Xiao-Ming ◽

...

Keyword(s):

Aluminum Alloy ◽

Corrosion Behavior ◽

Nacl Solution ◽

Micro Arc Oxidation

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

Scientific Bulletin of Valahia University - Materials and Mechanics ◽

10.2478/bsmm-2019-0013 ◽

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.

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