scholarly journals De-alloying Behavior of Mg–Al alloy in Sulphuric Acid and Acetic Acid Aqueous Solutions

Materials ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2046 ◽  
Author(s):  
Yonggang Li ◽  
Yinghui Wei ◽  
Shengqiang Yang
Keyword(s):  
Acetic Acid ◽  
Aqueous Solutions ◽  
Sulphuric Acid ◽  
Corrosion Behavior ◽  
Eutectic Phase ◽  
Al Alloy ◽  
General Corrosion ◽  
H2so4 Solution ◽  
Corrosion Characteristic ◽  
Selective Corrosion

The fabricated Mg–Al alloy consists of α-Mg phase and Mg–Mg17Al12 eutectic phase. The corrosion behavior of cast Mg–Al alloy in sulphuric acid (H2SO4) and acetic acid (HAc) aqueous solutions was investigated. The Mg–Al alloy shows general corrosion in H2SO4 solution, and the α-Mg dendrites revealed a slightly faster corrosion rate than that of the eutectics. In HAc solution, the alloy shows an obvious selective corrosion characteristic, with the α-Mg dendrites being corroded preferentially. Grain orientation plays an important role in corrosion behavior of the alloy in the HAc solutions.

scholarly journals Effect of Structural Modification on Corrosion Behavior of Hypo Eutectic Al-Si Alloy

2018 ◽  
Vol 778 ◽  
pp. 16-21
Author(s):  
Muhammad Mansoor ◽  
Muhammad Kamran Yaseen ◽  
Shaheed Khan
Keyword(s):  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Earth Metal ◽  
Alloy System ◽  
Eutectic Phase ◽  
Al Alloy ◽  
General Corrosion ◽  
Corrosion Properties ◽  
Unmodified Alloy ◽  
Cast Alloys

Al-Si eutectic cast alloys are widely used in aeronautical and automobile industries where significantly high strength, toughness and wear resistance are required. This class of cast alloys exhibit relatively low corrosion resistance in brine environments. The mechanical properties of the alloy system mainly depend upon the shape of Si rich eutectic phase, which mainly has acicular geometry. In present research, the effect of modified microstructure of 12 wt. % Si-Al alloy on corrosion behavior was studied. The needle like Si rich eutectic phase was modified to disperse spherical structure using rare earth metal halides. The corrosion rate and pitting behavior of modified and unmodified alloy were evaluated in 3.5% NaCl solution by general corrosion for calculated time. It was observed that the corrosion rate and pitting tendency of modified alloy had been appreciably reduced as compare to unmodified alloy. The improvement of corrosion properties were the attributes of changed morphology and distribution of Si rich eutectic phase.

scholarly journals Corrosion Behavior of AlFeCrCoNiZrx High-Entropy Alloys in 0.5 M Sulfuric Acid Solution

Metals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1471
Author(s):  
Yuhong Yao ◽  
Yaohua Jin ◽  
Wei Gao ◽  
Xiaoyu Liang ◽  
Jian Chen ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Potentiodynamic Polarization ◽  
General Corrosion ◽  
High Entropy Alloys ◽  
H2so4 Solution ◽  
High Entropy ◽  
Polarization Measurements ◽  
Selective Corrosion

AlCoCrFeNiZrx (x = 0, 0.1, 0.2, 0.3, and 0.5) high-entropy alloys (HEAs) were prepared by a non-consumable vacuum arc melting technology, and the microstructure and corrosion behavior were investigated by XRD, SEM, immersion tests, and electrochemical measurements. The results indicate that galvanic corrosion of the AlCoCrFeNiZrx alloys occurred in 0.5 M H2SO4 solution, and only 0.1 mol of the added Zr could greatly improve the corrosion resistance of the alloys. The corrosion properties of the AlCoCrFeNiZrx HEAs had similar change tendencies with the increase in the Zr content in the immersion tests, potentiodynamic polarization measurements, and electrochemical impedance analysis, that is, the corrosion resistance of the AlCoCrFeNiZrx alloys in a 0.5 M H2SO4 solution first increased and then decreased with the increase in the Zr content. The Zr0.1 alloys were found to have the best selective corrosion and general corrosion resistance with the smallest corrosion rate, whereas the Zr0.3 alloys presented the worst selective corrosion and general corrosion resistance with the highest corrosion rate from both the immersion tests and the potentiodynamic polarization measurements.

Transformation between localized and general corrosion behavior of die‐cast AZ91D magnesium alloy in 3.5 wt% NaCl aqueous solutions

2019 ◽  
Vol 70 (12) ◽  
pp. 2303-2310 ◽  
Author(s):  
Shaohua Zhang ◽  
Lifeng Hou ◽  
Huayun Du ◽  
Huan Wei ◽  
Baosheng Liu ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Aqueous Solutions ◽  
Corrosion Behavior ◽  
General Corrosion ◽  
Az91d Magnesium Alloy ◽  
Die Cast

Investigations of corrosion behaviour of SnSb12Cu6Pb alloy in 0.1M H2SO4 and 0.5M NaCl solution

2020 ◽  
Vol 1 (101) ◽  
pp. 5-14
Author(s):  
J. Hrabia-Wiśnios ◽  
B. Leszczyńska-Madej ◽  
R. Kowalik
Keyword(s):  
Aqueous Solution ◽  
Corrosion Resistance ◽  
Sulfuric Acid ◽  
Sodium Chloride ◽  
Aqueous Solutions ◽  
Corrosion Behavior ◽  
Electrochemical Corrosion ◽  
Working Environment ◽  
Nacl Solution ◽  
Selective Corrosion

Purpose: The results presented the microstructure and corrosive behavior of SnSb12Cu6Pb alloy (B82) in H2SO4 aqueous solution and NaCl aqueous solution. Design/methodology/approach: The electrochemical corrosion has been investigated in two different aqueous solutions: 0.1M sulfuric acid (H2SO4) and 0.5M sodium chloride (NaCl) solution measuring of potential changes relative to immersion time and conducting mass loss test. Microscopic investigations before and after corrosion tests were made using scanning electron microscopy. Findings: The obtained results indicate very good corrosion resistance of the alloy tested in NaCl solution. Corrosion progresses faster in a sulfuric acid aqueous solution compared to sodium chloride aqueous solution. Also, it was found that the dominant mechanism of corrosion degradation in both solutions is selective corrosion which is a particularly undesirable type of corrosion because it involves the loss of one alloying component and the formation of porous structure on the alloy surface. Research limitations/implications: The aqueous solutions used in this study are not a natural working environment of the bearing. However, a comparison of acidic and neutral solutions allows explaining the corrosion behavior of tin babbitts due to contaminants of oil lubricants. Further research should be conducted in more aggressive environments characteristic of industrial conditions. Practical implications: One of the important properties of bearing alloys are corrosion resistance. Corrosion properties are extremely important for the transport and storage of metallic components before they are used. Also, the working environment can have a destructive effect on the properties of the materials used. Industry environment, aging stagnant oil, and some acids may lead to selective corrosion of the tin, copper, lead, or antimony components and leaving a rough and weakened the babbitt surface. Electrochemical corrosion can contribute to the acceleration of bearing wear and consequent to bearing damage. Originality/value: Studies of the corrosion of tin-babbitt bearings are not extensive in the literature due to rare tin corrosion. This study could be an important complement to knowledge about the corrosion behavior of tin-based bearing alloys.

Effect of cold rolling on the corrosion behavior of Ta-4W alloy in sulphuric acid

2020 ◽  
Vol 176 ◽  
pp. 108924
Author(s):  
Guoqiang Ma ◽  
Guilin Wu ◽  
Wei Shi ◽  
Song Xiang ◽  
Qiang Chen ◽  
...  
Keyword(s):  
Cold Rolling ◽  
Sulphuric Acid ◽  
Corrosion Behavior

Valorization of a natural residue (sawdust) as adsorbent to remove the acetic acid in aqueous solutions

2015 ◽  
Vol 56 (10) ◽  
pp. 2731-2738 ◽  
Author(s):  
Kamel Rida ◽  
Atika Bouanika ◽  
Meriem Boudellal ◽  
Ali Boukhemkhem
Keyword(s):  
Acetic Acid ◽  
Aqueous Solutions

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.

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