Electrochemical corrosion behavior and surface passivation of bulk nanocrystalline copper in alkaline solution

2020 ◽  
Vol 67 (5) ◽  
pp. 465-472
Author(s):  
Wei Luo ◽  
Lei Hu ◽  
Yimin Xv ◽  
Jian Zhou ◽  
Wentao Xv ◽  
...  
Keyword(s):  
Grain Size ◽  
Corrosion Resistance ◽  
Passive Film ◽  
Corrosion Behavior ◽  
Potentiodynamic Polarization ◽  
Electrochemical Corrosion ◽  
Content Type ◽  
Naoh Solution ◽  
Electrochemical Corrosion Behavior ◽  
Bulk Nanocrystalline

Purpose This paper aims to focus on an assessment of the electrochemical corrosion performance of bulk NC copper in a variety of corrosion environments. Design/methodology/approach The electrochemical corrosion behavior of bulk nanocrystalline (NC) copper prepared by inert gas condensation and in situ warm compress technique was studied by using potentiodynamic polarization and electrochemical impedance spectroscopy tests in de-aerated 0.1 M NaOH solution. Findings NC copper exhibited a typical active-passive-transpassive behavior with the formation of duplex passive films, which was qualitatively similar to coarse-grain (CG) copper. Although a compact passive film formed on NC copper surface, the corrosion resistance of NC copper was lower in comparison with CG copper. The increase in corrosion rate for NC copper was mainly attributed to the high activity of surface atoms and intergranular atoms. These atoms led to an enhancement of passive ability and an increase of dissolution rate of passive film in oxygen-deficiency solution. For NC copper, the corrosion resistance decreased as grain size increased in NC range. Originality/value The difference in corrosion resistance between bulk NC copper and its CG counterpart is dependent upon the corrosion solution. In a previous work, the potentiodynamic polarization tests revealed that NC copper bulks (grain size 48, 68, 92 nm) had identical corrosion resistance to CG copper bulk in naturally aerated 0.1 M NaOH solution. The results might be related to the dissolved oxygen in the medium.

Electrochemical Corrosion Behavior of Different Graphite Shapes Cast Irons in Acidic Solution

2014 ◽  
Vol 906 ◽  
pp. 275-282
Author(s):  
Zhu Huan Yu ◽  
Jun Feng Qiang ◽  
Hui Lu Li
Keyword(s):  
Electron Microscopy ◽  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Driving Force ◽  
Acidic Solution ◽  
Electrochemical Corrosion ◽  
White Iron ◽  
Cast Irons ◽  
The Matrix ◽  
Electrochemical Corrosion Behavior

The effect of graphite shapes on the electrochemical corrosion behavior of cast iron was studied by means of weight loss tests, electrochemical measurements and electron microscopy. It was found that the electrochemical corrosion behavior of graphite is significantly different from one other, and the corrosive potential difference between carbide ad the matrix is the main driving force of the different phase corrosions. Among them, the center A type and edge D type graphite exhibited the highest corrosion resistance. The corrosion of white iron is worst, because there are so many type carbides in white iron and so there is an obvious tendency to produce micro-cell in white iron.

Effect of high temperature compression deformation strain rate on the microstructure and corrosion behavior of 2205 duplex stainless steel

2015 ◽  
Vol 62 (3) ◽  
pp. 163-171 ◽  
Author(s):  
Yinhui Yang ◽  
Biao Yan
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Strain Rate ◽  
Duplex Stainless Steel ◽  
Corrosion Behavior ◽  
Potentiodynamic Polarization ◽  
Phase Interface ◽  
Content Type ◽  
2205 Duplex Stainless Steel

Purpose – The aim of this paper was to investigate the effect of strain rate on microstructure and corrosion behavior of 2205 duplex stainless steel, after high-temperature compression tests. Design/methodology/approach – The specimens were prepared using a Gleeble3800 thermo-simulation machine over a range of temperatures from 850 to 1,250°C and strain rates from 0.005 to 5 s−1, and the corresponding flow curves and deformation microstructure obtained were further analyzed. To evaluate the effect of strain rate on corrosion behavior, potentiodynamic polarization tests and double-loop electrochemical potentiodynamic reactivation (DL-EPR) were used to characterize the electrochemical performance. Findings – Compared with strain rate of 0.5 s−1, the worst corrosion resistance behavior from the potentiodynamic polarization test results after deformation at 0.005 s−1 was attributed to more austenite (γ) and ferrite (δ) grain boundaries or δ/γ phase interface formation due to the better effect of γ dynamic recrystallization (DRX) or δ dynamic recovery (DRV). Increasing strain rate to 5 s−1 lowered the corrosion resistance, due to the increase in dislocation density. At the low strain rate of 0.005 s−1, the susceptibility to intergranular corrosion (IGC) was comparatively high after deformation at 1050 and 1150°C with more γ/γ grains and δ/γ phase boundary formation, which was lowered with the strain rate increase to 0.5 s−1, due to suppressing effect of γ DRX. Originality/value – The paper provides the scientific basis for the practical application of hot working of 2205 duplex stainless steel.

Effect of the Grain Size on Electrochemical Corrosion Behavior of Cu60Ni20Cr20 Alloys in Solutions Containing Chloride Ions

2012 ◽  
Vol 476-478 ◽  
pp. 16-20
Author(s):  
Guo De Li ◽  
Jing Bian ◽  
Zhong Qiu Cao ◽  
Ke Zhang ◽  
Ya Jun Fu
Keyword(s):  
Grain Size ◽  
Corrosion Behavior ◽  
Electrochemical Corrosion ◽  
Chloride Ion ◽  
Chloride Ions ◽  
Coarse Grained ◽  
Protective Film ◽  
Ion Concentrations ◽  
Corrosion Rates ◽  
Electrochemical Corrosion Behavior

The two Cu60Ni20Cr20alloys with the different grain size were prepared by conventional casting (CA) and mechanical alloying (MA) through hot pressing. Effect of the grain size on electrochemical corrosion behavior of the two Cu60Ni20Cr20 alloys was also studied in solutions containing chloride ions. Results show that the free corrosion potentials of the two alloys move toward to negative values, corrosion current densities increase and therefore corrosion rates become faster with the increment of chloride ion concentrations. CACu60Ni20Cr20alloy and MACu60Ni20Cr20alloy have passive phenomena in 0.05mol/L Na2SO4 neutral solution, but passive phenomena become weak or disappear when the chloride ions are added. Corrosion rates of the nanocrystalline MACu60Ni20Cr20alloy become slower than those of the coarse grained CACu60Ni20Cr20alloy in solutions containing the same chloride ion concentrations because MACu60Ni20Cr20alloy is able to produce large concentrations of grain boundaries and passive elements is able to diffuse quickly to form the protective film.

Effect of High-Intensity Pulsed Ion Beam Irradiation on the Electrochemical Corrosion Behavior of AZ31 Magnesium Alloy

2011 ◽  
Vol 189-193 ◽  
pp. 571-574
Author(s):  
Peng Li
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Corrosion Behavior ◽  
Current Density ◽  
Ion Beam ◽  
Electrochemical Corrosion ◽  
Corrosion Current ◽  
Open Circuit ◽  
Electrochemical Corrosion Behavior ◽  
Shot Number

HIPIB irradiation experiment is carried out at a specific ion current density of 1.1 J/cm2 with shot number from one to ten in order to explore the effect of shot number on electrochemical corrosion behavior of magnesium alloy. Surface morphologies, microstructure and corrosion resistance of the irradiated samples are examined by scanning electron microscopy (SEM), transmission electron microscope (TEM) and potentiodynamic polarization technique, respectively. It is found that HIPIB irradiation leads to the increase in open circuit potential, corrosion potential and breakdown potential, and the decrease in the corrosion current density and the corrosion rate as compared to the original sample. The improved corrosion resistance is mainly attributed to the grain refinement and surface purification induced by HIPIB irradiation.

Study on Electrochemical Corrosion Behavior Comparison between DLC and TiN Coatings under Different Corrosive Environment

2013 ◽  
Vol 750-752 ◽  
pp. 1977-1981 ◽  
Author(s):  
Wen Zhu ◽  
Chao Yin Nie ◽  
Chun Hua Ran ◽  
Yi Dong Jin ◽  
Yang Zhao
Keyword(s):  
Corrosion Resistance ◽  
Electrochemical Corrosion ◽  
Amorphous Structure ◽  
Tin Coating ◽  
Dlc Coating ◽  
Tin Coatings ◽  
Nano Crystalline ◽  
304 Austenitic Stainless Steel ◽  
Naoh Solution ◽  
Electrochemical Corrosion Behavior

Diamond-like carbon (DLC) and TiN coatings were deposited on the 304 austenitic stainless steel(SUS304) substrates by using unbalanced magnetron sputtering and arc ion plating techniques, respectively. The phase structure and surface morphology of coatings were characterized by SEM and XRD.The electrochemical corrosion of two coatings in different electrochemical solutions (including3.5%NaCl,10%HCl,20%NaOH) were investigated by electrochemical workstation.The result showed that DLC coating was amorphous structure and TiN coating was nano-crystalline structure.The surface of DLC coating was smooth and dense,while TiN coating existed pits.In 10%HCl and 3.5%NaCl solutions,the corrosion resistance of DLC coating increased by 4.16 and 10.9 times compared with SUS304 and increased by 5.16 and 1.11 times compared with TiN coating,respectively.But in 20%NaOH solution, the corrosion resistance of DLC was not superior to SUS304 and TiN coating.In 10%HCl solution,the corrosion resistance of TiN coating increased by 9.81 times compared with 304 SUS304.But in 3.5%NaCl and 20%NaOH solutions,the corrosion resistance of TiN coating was worse than SUS304.

Thermal Parameters Influence Assessed by Electrochemical Impedance Spectroscopy on a Ni50Ti48Nb2 Shape Memory Alloy

2018 ◽  
Vol 69 (1) ◽  
pp. 86-90 ◽  
Author(s):  
Ioana Arina Gherghescu ◽  
Daniela Ionita ◽  
Sorin Ciuca ◽  
Ruxandra Elena Dumitrescu
Keyword(s):  
Corrosion Resistance ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Electrochemical Corrosion ◽  
Transformation Temperatures ◽  
Electrochemical Corrosion Behavior

This paper presents some electrochemical impedance spectroscopy research results concerning the corrosion resistance of a shape memory Ni50Ti48Nb2 alloy. This one was previously studied by SEM and DSC [1,2] but some new research features had to be made clear in order to be able to explain its electrochemical corrosion behavior. The chemical composition Ni50Ti48Nb2 was chosen in order to obtain a shape memory alloy having a wider hysteresis than equiatomic NiTi, for the purpose of achieving a better thermomechanical stability. Cryogenic applications are aimed. After processing the cast ingot, two samples, S1 and S2, were further annealed at 800�C/12 h and, respectively, at 900�C/12h. Scanning electron micrographs together with the chemical elements mapping results were obtained. They were related to the previous results concerning the informations on the structure of the different phases found in this NiTiNb alloy: austenite, martensite and secondary phases, as well as some primary compounds [1,2]. Considering the size and shape of the complex precipitate particles of NiTiNb in the two differently heat treated samples, these were found responsible for some changes in the transformation temperatures [3] but the electrochemical corrosion behavior of the alloy seems to be influenced to a lesser extent by the heat treatments. Both samples exhibit good values of corrosion resistance, however S2 shows better values than S1. Thus lower transformation temperatures and a slightly better corrosion resistance make the Ni50Ti48Nb2 alloy annealed at 900�C/12h subsequently submitted to thermal cycling to be the right choice for producing couplings in the cryogenic industry.

scholarly journals Investigation of the Microstructure, Hardness and Corrosion Resistance of a New 58Ag24Pd11Cu2Au2Zn1.5In1.5Sn Dental Alloy

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4199 ◽  
Author(s):  
Dan Gheorghe ◽  
Ion Pencea ◽  
Iulian Vasile Antoniac ◽  
Ramona-Nicoleta Turcu
Keyword(s):  
Solid Solution ◽  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Artificial Saliva ◽  
Complex Structure ◽  
Electrochemical Corrosion ◽  
Dental Alloy ◽  
Dental Alloys ◽  
Cu Content ◽  
Electrochemical Corrosion Behavior

Higher-noble dental alloys (Au, Ag, and Pd) are the most desirable for dentistry applications, but they are expensive. Low-noble (Ag, Pd, Cu) dental alloys are alternatives to higher-noble ones due to their lower price. In this regard, the paper supports the price lowering of dental alloy by increasing the Cu content, i.e., a new 58Ag24Pd11Cu2Au2Zn1.5In1.5Sn dental alloy. The increasing addition of the Cu leads to a complex structure consisting of a solid solution that engulfs compounds of micrometric and nanometric sizes. The 58Ag24Pd11Cu2Au2Zn1.5In1.5Sn has demonstrated a much better electrochemical corrosion behavior in artificial saliva compared to the Paliag and Unique White dental alloys. The improved corrosion behavior of the new alloy is supported by the diminishing of the Cu selective diffusion into the electrolyte due to its retaining into compounds and into Ag-Pd solid solution. Also, the synergic effects of Cu, Zn, In, Sn may improve the corrosion resistance, but they have strengthened the 58Ag24Pd11Cu2Au2Zn1.5In1.5Sn matrix. The main finding addressed in the paper consists in a new 58Ag24Pd11Cu2Au2Zn1.5In1.5Sn dental alloy with improved corrosion resistance in artificial saliva.

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