scholarly journals Effect of Passivation Potential on Passive Behavior and Corrosion Resistance of Ni-Cu-P Amorphous Coating in Alkaline Solution

2017 ◽  
pp. 1348-1361
Author(s):  
Jie Chen ◽  
Keyword(s):  
Corrosion Resistance ◽  
Alkaline Solution ◽  
Amorphous Coating ◽  
Passive Behavior ◽  
Passivation Potential

scholarly journals Effect of Al Content in the Mg-Based Alloys on the Composition and Corrosion Resistance of Composite Hydroxide Films Formed by Steam Coating

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1188 ◽  
Author(s):  
Takahiro Ishizaki ◽  
Tomohiro Miyashita ◽  
Momo Inamura ◽  
Yuma Nagashima ◽  
Ai Serizawa
Keyword(s):  
Aqueous Solution ◽  
Corrosion Resistance ◽  
Treatment Time ◽  
Mg Alloys ◽  
Mg Alloy ◽  
Potential Range ◽  
Protective Film ◽  
Al Content ◽  
Passive Behavior ◽  
Superior Corrosion Resistance

Mg alloys are expected to be used in fields of the transportation industry because of their lightweight property, however, they show low corrosion resistance. To improve the corrosion resistance, preparation of the protective film on Mg alloys is essential. In this study, composite hydroxide films were prepared on three types of Mg alloys with different aluminum contents—that is, AZ31, AZ61, and AZ91D—by steam coating to investigate the relationship between the Mg-Al layered double hydroxide (LDH) content in the film and the Al content in the Mg alloys. Scanning electron microscopy (SEM) observation demonstrated that films were formed densely on all Mg alloy surfaces. X-ray diffraction (XRD) analyses revealed that all films prepared on AZ61 and AZ91D were composed of Mg(OH)2, AlOOH, and Mg-Al LDH, while the film containing Mg(OH)2 and Mg-Al LDH were formed only on AZ31. The Mg-Al LDH content in the film prepared on AZ61 was relatively higher than those prepared on AZ31 and AZ91D. The content of AlOOH in the film increased with an increase in the Al content in the Mg alloys. The film thickness changed depending on the treatment time and type of Mg alloy. Polarization curve measurements in 5 mass% NaCl solution demonstrated that the film prepared on the AZ61 showed complete passive behavior within the potential range of −1.0 to −0.64 V. In addition, immersion tests in 5 mass% NaCl aqueous solution for 480 h demonstrated that the film on the AZ61 had superior durability against 5 mass% NaCl aqueous solution. These results indicated that the film on the AZ61 had the most superior corrosion resistance among all samples. The results obtained in this study suggest that the LDH content in the film could be related to the corrosion resistance of the film.

Corrosion resistance improvement of 45 steel by Fe-based amorphous coating

Vacuum ◽  
2018 ◽  
Vol 153 ◽  
pp. 39-42 ◽  
Author(s):  
Guokun Huang ◽  
Lidan Qu ◽  
Yunzhuo Lu ◽  
Yongzhe Wang ◽  
Hongge Li ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Amorphous Coating ◽  
Resistance Improvement

The Effect of Grain Size and Cl-Concentration on the Passive Behavior of Cu in Borate Buffer Solution

2013 ◽  
Vol 785-786 ◽  
pp. 928-932 ◽  
Author(s):  
Qi Jun Zhong ◽  
Li Bin Yu ◽  
Yi Xiao ◽  
Yi Wang ◽  
Qiong Yu Zhou ◽  
...  
Keyword(s):  
Grain Size ◽  
Electrochemical Analysis ◽  
Borate Buffer ◽  
Borate Buffer Solution ◽  
Buffer Solution ◽  
Solution Ph ◽  
Passivation Film ◽  
Passive Behavior ◽  
Anode Passivation ◽  
Passivation Potential

Effect of grain size and Cl-concentration on corrosion behavior of Cu was investigated by using a series of electrochemical analysis in borate buffer solution (pH=8.40).The results indicated that in all cases, the Mott-Schottky plots of the passive films on the surface of Cu were linear with negative slop, and showed behavior of the p-type semiconductor.With the decrease of the grain size and the increase of anode passivation potential, the acceptor density (NA) of the passivation film on the surface of Cu was reducing. As the concentration of Cl-in the medium solution was heightening, the acceptor density (NA) of the passivation film on the surface of Cu was increasing.

Corrosion Characteristics of Surface-Modified DET Magnesium Powders

2004 ◽  
Vol 449-452 ◽  
pp. 369-372
Author(s):  
W.S. Chung ◽  
W.Y. Yoon ◽  
Kwang Jin Kim
Keyword(s):  
Corrosion Resistance ◽  
Surface Layer ◽  
Current Density ◽  
Nacl Solution ◽  
Composition Distribution ◽  
Passive Behavior ◽  
Modified Surfaces ◽  
Modified Surface ◽  
Surface Modified ◽  
Modified Surface Layer

Magnesium powders having inactive surface layer have been processed easily and intentionally by DET under fluoride, chromate, and bromide salt. The modified surfaces play an important role in preventing contact with active environments to improve corrosion resistance of Magnesium powders; the image of the surface modified powders was observed using SEM. The composition distribution and characteristics was determined and analyzed by using XRD, XPS, and EIS. Compared with bare Magnesium, the Magnesium having chromate modified surface layer showed a more passive behavior such as smaller current density and nobler potential in 4wt% NaCl solution.

The passive properties of TA10 in Coca-Cola containing oral environment

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ming Liu ◽  
Jun Li ◽  
Danping Li ◽  
Lierui Zheng
Keyword(s):  
Corrosion Resistance ◽  
Passive Film ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Artificial Saliva ◽  
Corrosion Current ◽  
Content Type ◽  
Passive Behavior ◽  
Tooth Demineralization ◽  
Oral Environment

Purpose At present, carbonated drinks such as cola are especially favored by the younger generation. But because of its acid, it often leads to tooth demineralization, resulting in “cola tooth”. However, the influence of cola on the corrosion resistance of passive film of TiA10 alloy restorative materials is rarely reported. The purpose of this study was to analysis the corrosion resistance, composition of the passive film of TA10 alloy in different concentrations of Cola. Design/methodology/approach The passive behavior of TA10 alloy in artificial saliva (AS) and Cola was studied by means of potentiodynamic polarization, electrochemical impedance spectroscopy, cyclic voltammetry, Mott-Schottky techniques and combined with X-ray photoelectron spectroscopy and Auger electron spectroscopy (AES) surface analysis. Findings With the increase of cola content, the self-corrosion current density of the alloy increases sharply, and the corrosion resistance of the passive film is the best in AS, while Rp in cola is reduced to half of that in AS. The thickness of the passive film in AS, AS +cola and cola is about 9.5 nm, 7.5 nm and 6 nm, respectively. The passive film in cola has more defects and the carrier density is 1.55 times as high as that in AS. Cola can weaken the formation process of the protected oxide, promote the formation of high valence Ti-oxides and increase the content of Mo-oxides in the passive film. Originality/value These results have important guiding significance for the safe use of the alloy in the complex oral environments.

Synthesis of Fe–Cr–Mo–C–B amorphous coating with high corrosion resistance

2012 ◽  
Vol 89 ◽  
pp. 229-232 ◽  
Author(s):  
Yongjiang Huang ◽  
Yuanzhi Guo ◽  
Hongbo Fan ◽  
Jun Shen
Keyword(s):  
Corrosion Resistance ◽  
Amorphous Coating ◽  
High Corrosion Resistance ◽  
High Corrosion

scholarly journals CORROSION BEHAVIOR OF THE ELECTROLYTIC TERNARY COBALT ALLOYS WITH Mo(W) AND Zr IN ALKALINE SOLUTION

2019 ◽  
Vol 85 (12) ◽  
pp. 96-109
Author(s):  
Maryna Ved’ ◽  
Nikolay Sakhnenko ◽  
Tatyana Nenastina ◽  
Iryna Yermolenko ◽  
Valerya Proskurina ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Alkaline Solution ◽  
Total Content ◽  
Ternary Alloys ◽  
X Ray Diffraction ◽  
High Electrical Resistivity ◽  
Diffraction Patterns ◽  
Electrolytic Alloys ◽  
Zr Alloys

The ternary Co–Mo–W(Zr) coatings with total content of refractory metals of 30–40 wt.%, and Co–W–Zr alloys (12–26 wt.%) are deposited from pyrophosphate-citrate electrolytes in pulse regime. The composition of the coatings as well as the surface morphology depends on the current density. The X-ray diffraction patterns reflect the amorphous-and-crystalline ternary alloys structure. Phases of α-Co, Co–Mo intermetallic compounds, and traces of metallic molybdenum were detected in the Co–Mo–Zr coatings. Phase composition of Co–Mo–W deposits differs by emergence of Co7W6 phase and traces of metallic tungsten, and there is no metallic W in Co–W–Zr electrolytic alloys. The corrosion behavior of ternary coatings in alkaline medium studied by EIS shows that Co–Mo–Zr alloys are characterized by highest corrosion resistance among deposited coatings due to presence of metallic molybdenum and stoichiometric ZrO2 with both high electrical resistivity and chemical stability. The coatings  Co–Mo–W and Co–Mo–Zr containing phases of Mo or W are characterized by higher corrosion resistance as compared with that without metallic molybdenum and tungsten. The cyclic voltammetry data confirm stability of ternary coatings in alkaline solution under anodic polarization. Such properties as well as the developed globular surface make materials promising for use as anodes in fuel cells in particular based on alkali electrolytes.

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