Cavitation Corrosion Behavior of Anodized Aluminum Alloy

CORROSION ◽  
2011 ◽  
Vol 67 (9) ◽  
pp. 095003-095003-5 ◽  
Author(s):  
X. Yong ◽  
C. Hou ◽  
J. Wu ◽  
Z. Zhang ◽  
D. Li

Abstract The cavitation corrosion behavior and surface morphology of anodized aluminum alloy in 3.5% sodium chloride (NaCl) solution were investigated using weight loss and scanning electron microscopy. The electrochemical corrosion mechanism during cavitation corrosion was studied using electrochemical polarization and electrochemical impedance spectroscopy (EIS). The cavitation corrosion process could be divided into three stages: quick removal of the porous outer layer, slowly fragmenting and removing of the dense inner layer, and fast erosion of the aluminum alloy. Increasing the thickness of the anodized layer improved the cavitation corrosion resistance of the anodized aluminum alloy. Electrochemical corrosion processes under cavitation conditions were controlled by mixed cathodic and anodic processes. EIS spectra of anodized aluminum alloy under cavitation conditions resembled those from porous electrodes. Cavitation accelerated the electrochemical corrosion. Cavitation corrosion of anodized aluminum alloy showed strong synergism between mechanical and electrochemical corrosion factors.

Materials ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 2614 ◽  
Author(s):  
Xiuqing Fu ◽  
Wenke Ma ◽  
Shuanglu Duan ◽  
Qingqing Wang ◽  
Jinran Lin

In order to study the effect of nano-CeO2 particles doping on the electrochemical corrosion behavior of pure Ni-Fe-Co-P alloy coating, Ni-Fe-Co-P-CeO2 composite coating is prepared on the surface of 45 steel by scanning electrodeposition. The morphology, composition, and phase structure of the composite coating are analyzed by means of scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD). The corrosion behavior of the coatings with different concentrations of nano-CeO2 particles in 50 g/L NaCl solution is studied by Tafel polarization curve and electrochemical impedance spectroscopy. The corrosion mechanism is discussed. The experimental results show that the obtained Ni-Fe-Co-P-CeO2 composite coating is amorphous, and the addition of nano-CeO2 particles increases the mass fraction of P. With the increase of the concentration of nano-CeO2 particles in the plating solution, the surface flatness of the coating increases. The surface of Ni-Fe-Co-P-1 g/L CeO2 composite coating is uniform and dense, and its self-corrosion potential is the most positive; the corrosion current and corrosion rate are the smallest, and the charge transfer resistance is the largest, showing the best corrosion resistance.


2013 ◽  
Vol 341-342 ◽  
pp. 23-27
Author(s):  
Wei Cai ◽  
An Yun Li ◽  
Pian Xu ◽  
Yu Wu ◽  
Liang Chen ◽  
...  

Investigating the electrochemical corrosion behavior of Cu15Ni10Mn alloy in NaCl solution with different Cl concentration was studied by measuring open-circuit potential, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and cyclic voltammetry. The results show that as the Cl- concentration increase, the corrosion potentials of the alloy shifted negatively, corrosion currents increase, the corrosion process by electrochemical control change of diffusion control, and therefore the corrosion rates become faster. The presence of Cl- have effect on the dissolution mechanism and corrosion products of the alloy, when the concentration of Cl- is relatively low, a reducing peak current appears in the process of cyclic voltammetry retracing , when the Cl- concentration is higher, cyclic voltammetry flyback process does not appear to restore the current peak. This is mainly associated with the generation of corrosion product, when Cl- concentration is low, the corrosion product is Cu2(OH)3Cl (basic copper chloride) and other two copper ion salts, when the concentration of Cl-is higher, corrosion products are mainly Cu2(OH)3Cl (basic copper chloride).


2016 ◽  
Vol 863 ◽  
pp. 65-69
Author(s):  
Jing Chie Lin ◽  
Mao Chia Huang ◽  
Ongki B. Anggriawan ◽  
Jason Shian Ching Jang ◽  
M. Agus Choiron

Electrochemical corrosion of as-cast and annealed zirconium-based bulk metallic glass (BMG) Zr48Cu36Al8Ag8 in 0.1 M NaCl solution was investigated in this work. The as-cast specimen, in complete amorphous form, contained null percent of crystal phase (denoted as 0C); however, the annealed ones contained 11, 25, 50, 75 and 100 % crystal phase (denoted as 11C, 25C, 50C, 75C and 100C, respectively) determined by the annealing duration of 0C specimen at 471 °C. Through monitoring of open circuit potential (OCP), measurements of direct-current polarization resistance (PR), Tafel plot (TP), cyclic anodic potentiodynamic polarization (CAPD), and electrochemical impedance spectroscopy (EIS), we found that the corrosion behavior of the Zr48Cu36Al8Ag8 was detremined by the the crystal phase present in the specemns dominated by the annealing durations. The corrosion resistance decreased in the order: 25C > 11C > 0C > 50C > 75C > 100C. This result revealed that the corrosion resistance inclined to be better and reached a mxmium with increasing the percentgae of the crystal phase from 0 to 25%; however, it decreased with further increasing the crystal phase over 25%. A corrosion mechanism is proposed to rationalize the sequence of corrosion resistance. According to the mechanism, the remained free volume and residual strain energy are responsible for the specimens containing crystal phase less than 25% (i.e., 0C, 11C and 25C); whereas crystal defects such as grain boundaries governed the corrosion of those containing crystal phase more than 25 % (i.e., 50C, 75C and 100C).


2017 ◽  
Vol 24 (Supp01) ◽  
pp. 1850016 ◽  
Author(s):  
GAN TIAN ◽  
GUO-FENG JIN ◽  
WEI ZHANG ◽  
ZHI-YONG HUANG ◽  
ZHENG-WEI YANG

In order to evaluate the left life of the aircraft tank in the storage stage and enhance the reliability of aircraft, the electrochemical corrosion characteristic of 2A14 aluminum alloy has been investigated by the polarization curve method, electrochemical impedance spectroscopy methods and soaking corrosion test in this paper. The corrosion equivalent relationship of 2A14 aluminum alloy at different conditions was established. Moreover, the corrosion mechanism and law of 2A14 aluminum alloy in the solution of N2O4-HNO3 were obtained. It is shown that the nitric acid with the volume fraction of 30% corrodes 2A14 aluminum alloy had the fastest speed. The corrosion intensity of the specimen increases with the increase of the environment temperature. In the corrosion program, the corrosion is begun with the pit with very small size. As the time passes by, the pits expand and the adjacent pits combines together to be a larger pit. Finally, the thickness of the specimen decreases uniformly as the corrosion product peels off from the surface of the specimen. Therefore, the corrosion evaluation of aluminum alloy structure can be performed by weighting or measuring the thickness in application.


Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1317
Author(s):  
Hongmei Zhang ◽  
Ling Yan ◽  
Yangyang Zhu ◽  
Fangfang Ai ◽  
Hongnan Li ◽  
...  

In this paper, electrochemical corrosion tests and full immersion corrosion experiments were conducted in seawater at room temperature to investigate the electrochemical corrosion behavior and the corrosion mechanism of high-strength EH47. The polarization curve, EIS (electrochemical impedance spectroscopy), SEM (scanning electron microscope), and EDS analyses were employed to analyze the results of the electrochemical corrosion process. The electrochemical corrosion experiments showed that the open circuit potential of EH47 decreases and then increases with an increase in total immersion time, with the minimum value obtained at 28 days. With an increase in immersion time, the corrosion current density (Icorr) of EH47 steel first decreases and then increases, with the minimum at about 28 days. This 28-day sample also showed the maximum capacitance arc radius, the maximum impedance and the minimum corrosion rate. In the seawater immersion test in the laboratory, the corrosion mechanism of EH47 steel in the initial stage of corrosion is mainly pitting corrosion, accompanied by a small amount of crevice corrosion with increased corrosion time. The corrosion products of EH47 steel after immersion in seawater for 30 days are mainly composed of FeOOH, Fe3O4 and Fe2O3.


2015 ◽  
Vol 30 (6) ◽  
pp. 627
Author(s):  
YE Zuo-Yan ◽  
LIU Dao-Xin ◽  
LI Chong-Yang ◽  
ZHANG Xiao-Hua ◽  
ZANG Xiao-Ming ◽  
...  

2013 ◽  
Vol 83 (5) ◽  
pp. 864-869 ◽  
Author(s):  
Elisa J. Kassab ◽  
José Ponciano Gomes

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.


2014 ◽  
Vol 789 ◽  
pp. 622-626
Author(s):  
Peng Chao Zhang ◽  
Jian Zhang ◽  
Jin Chuan Jie ◽  
Yuan Gao ◽  
Yong Dong ◽  
...  

The effect of different alloying elements on corrosion behavior of copper alloys was investigated using electrochemical corrosion and salt spray corrosion test in NaCl solution. Cu-Ag has the most stable corrosion current in the potentiostatic scanning test, exhibiting a better corrosion resistant performance. It can be analyzed from corrosion surface morphologies that Cu-Ag presents exfoliation corrosion mechanism while Cu-Sn shows crevice corrosion mechanism. Cu-Mg has a complex corrosion process caused by multiple corrosion mechanism. In the salt spray corrosion test, the corrosion degree of Cu-Ag is lighter than those of Cu-Sn and Cu-Mg after 24h test. Therefore, the Cu-Ag alloy exhibits the best corrosion resistance in chloride solution.


2021 ◽  
Vol 904 ◽  
pp. 519-524
Author(s):  
Gui Yun Zhang ◽  
Yong Wang ◽  
Tian Wei Zhang ◽  
Chen Yu Zhao

Sea water resources are extensive and can be used to extinguish fires, but their corrosiveness is a major problem. Using the method of electrochemical workstation, the electrochemical corrosion behavior of aluminum sheet in artificial sea water solution and silica-coated artificial seawater was studied; by analyzing the surface morphology, polarization curve and electrochemical impedance spectroscopy, the electrochemical corrosion behavior of aluminum sheets under different immersion times and different immersion media is obtained. The conclusion is that the coating of nanosilica powder has a certain corrosion protection effect on artificial seawater.


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