Effect of Cr/Zr on the Electrochemical Behavior of Copper in NaCl/NaOH/HCl Solution

2011 ◽  
Vol 239-242 ◽  
pp. 1582-1585
Author(s):  
Ya Ni Zhang ◽  
Mao Sheng Zheng ◽  
Jie Wu Zhu
Keyword(s):  
Corrosion Resistance ◽  
Potentiodynamic Polarization ◽  
Corrosion Current Density ◽  
Room Temperature ◽  
Pure Copper ◽  
Corrosion Current ◽  
Passive Layer ◽  
Nacl Solution ◽  
Naoh Solution ◽  
Hcl Solution

The potentiodynamic polarization and cyclic voltommogroms studies were carried out on the copper with micro-addition of Cr and Zr in solutions of 0.5M NaCl, 0.5M NaOH and 0.5M HCl at room temperature. The corrosion resistance of pure copper is deteriorated with addition of the alloying elements Cr and Zr. Significant reducing in the corrosion resistance is observed when Cr and Zr are added simultaneously. Moreover, the lowest corrosion current density is obtained in the NaCl solution followed by the NaOH solution and HCl solution. Compared with the different effect on the passive layer in the NaCl solution, the micro-addition of Cr and Zr leads to the increasing of the corrosion resistance for the passive layer in 0.5M NaOH solution and 0.5M HCl solution.

Effect of Osmotic Pressure by Salt Concentration on Corrosion Resistance of Anti-Corrosive Paint

2018 ◽  
Vol 926 ◽  
pp. 31-36
Author(s):  
Kyung Man Moon ◽  
Myeong Hoon Lee ◽  
Tae Sil Baek
Keyword(s):  
Corrosion Resistance ◽  
Osmotic Pressure ◽  
Salt Concentration ◽  
Corrosion Current Density ◽  
Steel Plate ◽  
Chloride Ion ◽  
Corrosion Current ◽  
Coating Film ◽  
Coated Steel ◽  
Nacl Solution

Recently, many types of constructional steels have been often exposed to severely corrosive environments due to acid rain with increasing environmental contamination. To control corrosion problems, a painting protection method has been widely applied to numerous constructional steels on land as well as offshore. Therefore, development of anti-corrosive paint with good quality of corrosion resistance is very important from an economical perspective. In this study, four types of anti-corrosive paint were coated to test specimens, and then, were immersed in various salt solutions (0.1, 3 and 9% NaCl solution) for 11 days. Corrosion resistance of these samples by effect of osmotic pressure with various salt concentration was investigated with electrochemical methods such as measurement of corrosion potential, impedance and corrosion current density. Corrosion current density of these samples submerged in 0.1% NaCl solution exhibited highest value than those immersed in 3% and 9% NaCl solutions because water, dissolved oxygen and chloride ion etc. is easily to invade towards inner side of coating film due to increasing osmotic pressure compared to 3% and 9% NaCl solutions. However, corrosion current densities of all samples in the case of submerged in 9% NaCl solution exhibited higher values compared to 3% NaCl solution.Thus, a large amount of chloride ion dissolved in 9% NaCl solution plays a more critical role in corrosion behavior of coated steel rather than osmotic pressure. Consequently, the corrosion mechanism between coated steel and bare steel plates is different from each other because of presence of osmotic pressure between salt solution and coating film of coated steel plate. As a result, corrosion resistance of tcoated steel plate may be depend on the osmotic pressure as well as salt concentration

Electroless Ni-Co-P Coatings on Sintered Nd-Fe-B Magnets with Improved Corrosion Resistance

2009 ◽  
Vol 75 ◽  
pp. 53-56 ◽  
Author(s):  
Tian Yu Ma ◽  
Hua Gen Ying ◽  
Mi Yan
Keyword(s):  
Magnetic Properties ◽  
Corrosion Resistance ◽  
Corrosion Current Density ◽  
Permanent Magnets ◽  
Corrosion Current ◽  
Operating Conditions ◽  
Slight Reduction ◽  
Bath Composition ◽  
Nacl Solution ◽  
Electroless Ni

Electroless Ni-Co-P coatings have been deposited on sintered Nd-Fe-B permanent magnets by optimizing the bath composition and operating conditions. The corrosion resistance of coated Nd-Fe-B magnets was significantly improved and corresponding corrosion current density Icorr in 3.5 wt. % NaCl solution decreased by two orders of magnitude. Coated with 12μm-thick Ni-Co-P, Nd-Fe-B magnets possessed slight reduction in magnetic properties, with a modest loss of remanence (Br) by 3.9 % and coercivity (iHC) by 4.5 %.

Corrosion Behaviour of Amorphous and Nanocrystalline Ti60Ni40 in Aqueous HNO3 Solution

2009 ◽  
Vol 67 ◽  
pp. 173-178 ◽  
Author(s):  
Shubhra Mathur ◽  
Rishi Vyas ◽  
S.N. Dolia ◽  
Kanu Sachdev ◽  
S.K. Sharma
Keyword(s):  
Weight Loss ◽  
Potentiodynamic Polarization ◽  
Corrosion Current Density ◽  
Room Temperature ◽  
Corrosion Behaviour ◽  
Aqueous Media ◽  
Amorphous State ◽  
Corrosion Current ◽  
Nanocrystalline State ◽  
Polarization Studies

Potentiodynamic polarization studies were carried out on amorphous, nanocrystalline and crystalline states of the alloy Ti60Ni40 in 0.1 M HNO3, 0.5 M HNO3 and 1 M HNO3 aqueous solutions at room temperature. It was observed that the amorphous state exhibited higher corrosion current density than that by the nanocrystalline state. These results are corroborated by the weight loss studies performed on the different structural states of Ti60Ni40 alloy in 0.1 M HNO3, 0.5 M HNO3 and 1 M HNO3 aqueous media. Thus the nanocrystalline state is least prone to corrosion than the amorphous and the crystalline states.

scholarly journals Corrosion Behavior of Diffusion Bonding Joints of (OFHC) Copper with Stainless Steel 304L in 3.5% NaCl

2018 ◽  
Vol 21 (1) ◽  
pp. 74
Author(s):  
Sami Abualnoun Ajeel ◽  
Ahmed Ali Akbar Akbar ◽  
Safaa Mohammed Hassoni
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Current Density ◽  
Diffusion Bonding ◽  
Corrosion Current Density ◽  
Pure Copper ◽  
Corrosion Current ◽  
Stainless Steel 304L ◽  
Materials Used

The present work deals with direct diffusion bonding welding without interlayer of austenitic stainless steel type AISI 304L with Oxygen Free High Conductivity pure copper (OFHC) in vacuum atmosphere (1.5 *10-5 mbr.). The optimum bonding conditions are temperature of 650 ◦C, duration time of 45 min. and the applied stress of 30 MPa, in order to secure a tight contact between the mating surfaces. The corrosion behavior of diffusion bonding joints in 3.5% Nacl is studied to evaluate the corrosion resistance of welding joints by using Potentiodynamic method. The observed microstructure of corroded specimen of optimum diffusion bonding joint shows that the corrosion current density has low value as compared with base materials used. During polarization, galvanic coupling is observed between two materials used. At passivity region, inverse polarity is occurred at 450mV. Therefore, passive stainless steel 304 L behaves as cathode respective to pure copper, the corrosion behavior of the diffusion bonding joint was mostly by copper side. The corrosion results indicate the presence of galvanic effect. The corrosion current density of copper, stainless steel 304L and bond joints condition were (3.66 µA/cm2, 1.62 µA/cm2 and 1.85µA/cm2) respectively. A SEM examination of corroded diffusion bonding joint indicates that the galvanic corrosion happened on copper side. The corrosion rate of bonding joint conditions was 0.85 mpy, which is less than 1%. This means that corrosion resistance of bond joint is more than excellent.

Influence of Cr and Mn Addition and Heat Treatment on the Corrosion Behaviour of an AlSi3Mg Alloy

2017 ◽  
Vol 754 ◽  
pp. 11-14 ◽  
Author(s):  
Marialaura Tocci ◽  
Lorenzo Montesano ◽  
Annalisa Pola ◽  
Marcello Gelfi ◽  
Marina La Vecchia
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Corrosion Resistance ◽  
Corrosion Current Density ◽  
Corrosion Behaviour ◽  
Base Alloy ◽  
Corrosion Current ◽  
Nacl Solution ◽  
Heat Treated ◽  
Mechanical Properties And Corrosion

In the present work, the effect of Cr and Mn addition on corrosion resistance was investigated on AlSi3Mg alloy. Potentiondynamic corrosion tests in a 3.5 wt. % NaCl solution were performed on samples in different heat-treated conditions, and corrosion current density and potential were determined by Tafel method. Brinnel hardness measurements were also carried out in order to couple corrosion resistance with mechanical properties. It was interestingly found that Cr presence enhanced mechanical properties and corrosion resistance in comparison with the base alloy.

Preparation and Properties of Chrome-Free Colored Na3AlF6 Conversion Coating on Aluminum Alloy

2012 ◽  
Vol 490-495 ◽  
pp. 3527-3530 ◽  
Author(s):  
Ai Hua Yi ◽  
Wen Fang Li ◽  
Jun Du ◽  
Song Lin Mu
Keyword(s):  
Corrosion Resistance ◽  
Aluminum Alloy ◽  
Current Density ◽  
Potentiodynamic Polarization ◽  
Corrosion Current Density ◽  
Corrosion Current ◽  
Conversion Coating ◽  
Film Forming ◽  
Polarization Test ◽  
Main Component

By adding tannic acid and film-forming accelerator in the treatment solution containing titanium and zirconium ions, a golden conversion coating on the surface of aluminum alloy was prepared. The main component and corrosion resistance of the conversion coating were characterized by means of EDS, SEM, XRD and electrochemical workstation. The conversion coating was golden and showed as uniform cubical crystal. results also showed that the main component of the conversion coating was Na3AlF6. In potentiodynamic polarization test, the corrosion current density of the aluminum alloy decreases to 0.083 A•cm-2 from 5.894 A•cm-2, which indicated an obvious improvement of corrosion resistance.

The Roles of Ti Particles in Improving the Corrosion Resistance of Electrochemically Assembled Ni-Ti Composite Coatings

CORROSION ◽  
10.5006/2408 ◽  
2017 ◽  
Vol 73 (9) ◽  
pp. 1107-1118 ◽  
Author(s):  
Yuantao Zhao ◽  
Lianbo Wang ◽  
Zhenbo Qin ◽  
Chengxi Wang ◽  
Zhou Xu ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Composite Coatings ◽  
Corrosion Current ◽  
Localized Corrosion ◽  
Corrosion Mechanism ◽  
Nacl Solution ◽  
Oriented Texture ◽  
Naoh Solution ◽  
Order Of Magnitude ◽  
Ti Particles

The influences of co-deposited Ti particles on corrosion behavior of electrodeposited Ni-Ti coatings were investigated. The co-deposited Ti particles caused the refined crystallite size and random-oriented texture of Ni-Ti coating. In 3.5 wt% sodium chloride (NaCl) solution, the buried Ti particles in Ni matrix blocked the corrosion path and rapid intercrystalline corrosion. The inert TiO2 could form on the exposed Ti particles and hinder localized corrosion. In 10 wt% sodium hydroxide (NaOH) solution, Ni matrix crystallites, refined by co-deposited Ti particles, contributed to formation of the passive Ni(OH)2 film. The corrosion current of Ni-Ti coating decreased by about one order of magnitude in both solutions with respect to pure Ni coating, demonstrating the co-deposited Ti particles greatly improved the corrosion resistance of Ni-Ti composite coatings. Finally, a corrosion mechanism was built to explain the co-deposited Ti particles improved corrosion resistance of the Ni-Ti composite coatings.

scholarly journals Corrosion Behavior and Osteogenic Activity of a Biodegradable Orthopedic Implant Mg–Si Alloy with a Gradient Structure

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 781
Author(s):  
Weiyan Jiang ◽  
Wenzhou Yu
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Polarization Resistance ◽  
Corrosion Current Density ◽  
Corrosion Current ◽  
Gradient Structure ◽  
Orthopedic Implant ◽  
Biological Functions ◽  
Alloy Matrix ◽  
Osteogenic Activity

A gradient Mg-8 wt % Si alloy, which was composed of the agglomerated Mg2Si crystals coating (GMS8-1) and the eutectic Mg–Si alloy matrix (GMS8-2), was designed for biodegradable orthopedic implant materials. The bio-corrosion behavior was evaluated by the electrochemical measurements and the immersion tests. The results show that a significant improvement of bio-corrosion resistance was achieved by using the gradient Mg–Si alloy, as compared with the traditional Mg-8 wt % Si alloy (MS8), which should be attributed to the compact and insoluble Mg2Si phase distributed on the surface of the material. Especially, GMS8-1 exhibits the highest polarization resistance of 1610 Ω, the lowest corrosion current density of 1.7 × 10−6 A.cm−2, and the slowest corrosion rate of 0.10 mm/year. In addition, GMS8-1 and GMS8-2 show better osteogenic activity than MS8, with no cytotoxicity to MC3T3-E1 cells. This work provides a new way to design a gradient biodegradable Mg alloys with some certain biological functions.

scholarly journals Structure, Corrosion Resistance, Mechanical and Tribological Properties of ZrB2 and Zr-B-N Coatings

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1194
Author(s):  
Philipp Kiryukhantsev-Korneev ◽  
Alina Sytchenko ◽  
Yuriy Kaplanskii ◽  
Alexander Sheveyko ◽  
Stepan Vorotilo ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Tribological Properties ◽  
Current Density ◽  
Corrosion Current Density ◽  
Elastic Recovery ◽  
Optical Emission ◽  
Corrosion Current ◽  
Impact Testing ◽  
Total Oxidation ◽  
Mechanical And Tribological Properties

The coatings ZrB2 and Zr-B-N were deposited by magnetron sputtering of ZrB2 target in Ar and Ar–15%N2 atmospheres. The structure and properties of the coatings were investigated via scanning and transmission electron microscopy, energy dispersion analysis, optical profilometry, glowing discharge optical emission spectroscopy and X-ray diffraction analysis. Mechanical and tribological properties of the coatings were investigated using nanoindentation, “pin-on-disc” tribological testing and “ball-on-plate” impact testing. Free corrosion potential and corrosion current density were measured by electrochemical testing in 1N H2SO4 and 3.5%NaCl solutions. The oxidation resistance of the coatings was investigated in the 600–800 °С temperature interval. The coatings deposited in Ar contained 4–11 nm grains of the h-ZrB2 phase along with free boron. Nitrogen-containing coatings consisted of finer crystals (1–4 nm) of h-ZrB2, separated by interlayers of amorphous a-BN. Both types of coatings featured hardness of 22–23 GPa; however, the introduction of nitrogen decreased the coating’s elastic modulus from 342 to 266 GPa and increased the elastic recovery from 62 to 72%, which enhanced the wear resistance of the coatings. N-doped coatings demonstrated a relatively low friction coefficient of 0.4 and a specific wear rate of ~1.3 × 10−6 mm3N−1m−1. Electrochemical investigations revealed that the introduction of nitrogen into the coatings resulted in the decrease of corrosion current density in 3.5% NaCl and 1N H2SO4 solution up to 3.5 and 5 times, correspondingly. The superior corrosion resistance of Zr-В-N coatings was related to the finer grains size and increased volume of the BN phase. The samples ZrB2 and Zr-B-N resisted oxidation at 600 °C. N-free coatings resisted oxidation (up to 800 °С) and the diffusion of metallic elements from the substrate better. In contrast, Zr-B-N coatings experienced total oxidation and formed loose oxide layers, which could be easily removed from the substrate.

Effect of Cr and Zr Addition on the Corrosion Behaviour of Copper in the Chloride Solution

2011 ◽  
Vol 194-196 ◽  
pp. 1253-1256
Author(s):  
Ya Ni Zhang ◽  
Mao Sheng Zheng ◽  
Jie Wu Zhu
Keyword(s):  
Corrosion Resistance ◽  
Chloride Solution ◽  
Corrosion Behaviour ◽  
Pure Copper ◽  
Base Material ◽  
Nacl Solution ◽  
Corrosion Performance ◽  
Zr Addition ◽  
Corrosion Scales ◽  
Better Than

The corrosion behavior of CuCr, CuZr and CuCrZr alloys in NaCl solution is reported in this paper. The corrosion performance has been evaluated in NaCl solution atmosphere. The results show the corrosion resistance of pure copper decrease with the addition of the alloying elements initially. However, in the later exposure stages, the corrosion resistance of CuZr and CuCrZr alloy deteriorates significantly while the corrosion resistance of CuCr alloy is slightly better than that of pure copper. In addition, the results of the electrochemical experiments indicate that the different behavior for the element Cr and Zr in the base material and corrosion scales lead to the change of the corrosion resistance.

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