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.

scholarly journals Effect of Recrystallization Annealing on Corrosion Behavior of Ta-4%W Alloy

Materials ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 117 ◽  
Author(s):  
Guoqiang Ma ◽  
Qiongyao He ◽  
Xuan Luo ◽  
Guilin Wu ◽  
Qiang Chen
Keyword(s):  
Corrosion Resistance ◽  
Anodic Dissolution ◽  
Corrosion Behavior ◽  
Current Density ◽  
Polarization Resistance ◽  
Corrosion Current Density ◽  
Corrosion Potential ◽  
Corrosion Current ◽  
Recrystallization Annealing ◽  
Site Lattice

The effect of recrystallization annealing on corrosion behavior of Ta-4%W alloy was studied. It is found that the deformed sample contains high dense dislocations and dislocation boundaries. During annealing, these dislocations and dislocation boundaries are replaced by recrystallizing grains until the alloy is fully recrystallized. Both the anodic dissolution and the cathodic activity is much more blocked. The corrosion potential gradual shift towards negative values and corrosion current density decrease, while polarization resistance increases after annealing, indicating enhanced corrosion resistance of the alloy. Such an enhancement is caused by the increase of low-Σ coincide site lattice boundaries and decrease of dislocations and dislocation boundaries.

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.

scholarly journals Preparation of Ti–Zr-Based Conversion Coating on 5052 Aluminum Alloy, and Its Corrosion Resistance and Antifouling Performance

Coatings ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 397 ◽  
Author(s):  
Hehong Zhang ◽  
Xiaofeng Zhang ◽  
Xuhui Zhao ◽  
Yuming Tang ◽  
Yu Zuo
Keyword(s):  
Corrosion Resistance ◽  
Surface Modification ◽  
Aluminum Alloy ◽  
Current Density ◽  
Corrosion Current Density ◽  
Salt Water ◽  
Water Immersion ◽  
Chemical Conversion ◽  
Corrosion Current ◽  
Conversion Coating

A chemical conversion coating on 5052 aluminum alloy was prepared by using K2ZrF6 and K2TiF6 as the main salts, KMnO4 as the oxidant and NaF as the accelerant. The surface morphology, structure and composition were analyzed by SEM, EDS, FT–IR and XPS. The corrosion resistance of the conversion coating was studied by salt water immersion and polarization curve analysis. The influence of fluorosilane (FAS-17) surface modification on its antifouling property was also discussed. The results showed that the prepared conversion coating mainly consisted of AlF3·3H2O, Al2O3, MnO2 and TiO2, and exhibited good corrosion resistance. Its corrosion potential in 3.5 wt % NaCl solution was positively shifted about 590 mV and the corrosion current density was dropped from 1.10 to 0.48 μA cm−2. By sealing treatment in NiF2 solution, its corrosion resistance was further improved yielding a corrosion current density drop of 0.04 μA cm−2. By fluorosilane (FAS-17) surface modification, the conversion coating became hydrophobic due to low-surface-energy groups such as CF2 and CF3, and the contact angle reached 136.8°. Moreover, by FAS-17 modification, the corrosion resistance was enhanced significantly and its corrosion rate decreased by about 25 times.

Electrochemical Characteristics of Lanthanum Hexaboride in the Environments Containing S2-

2010 ◽  
Vol 663-665 ◽  
pp. 473-476
Author(s):  
Shu Qi Zheng ◽  
Chang Feng Chen ◽  
Rui Jing Jiang ◽  
Dan Ni Wang
Keyword(s):  
Partial Pressure ◽  
Corrosion Behavior ◽  
Current Density ◽  
Corrosion Current Density ◽  
Corrosion Potential ◽  
Corrosion Current ◽  
Lanthanum Hexaboride ◽  
Electrochemical Characteristics

In the environment with H2S/CO2 or Na2S, the corrosion behavior of Lanthanum hexaboride (LaB6) was investigated by electrochemistry methods. The results indicated that the corrosion potential (Ecorr) and Rf of LaB6 increased as the partial pressure of H2S increased, while the corrosion current density (Icorr) decreased. In the environment containing Na2S, as the content of Na2S increased, the corrosion potential (Ecorr) and Rf of LaB6 decreased, while the corrosion current density (Icorr) increased. Thus, the addition of H2S into the environment with H2S/CO2 would inhibit the corrosion of LaB6; while in the environment containing Na2S, the increasing of the content of Na2S would accelerate the corrosion of LaB6.

scholarly journals Low Temperature Sealing of Anodized Aluminum Alloy for Enhancing Corrosion Resistance

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4904
Author(s):  
Hyunbin Jo ◽  
Soomin Lee ◽  
Donghyun Kim ◽  
Junghoon Lee
Keyword(s):  
Corrosion Resistance ◽  
Aluminum Alloy ◽  
Current Density ◽  
Corrosion Current Density ◽  
Corrosion Current ◽  
Anodic Oxide ◽  
Nickel Acetate ◽  
Anodized Aluminum ◽  
Corrosive Media ◽  
Nickel Fluoride

Sealing as a post treatment of anodized aluminum is required to enhance the corrosion resistance by filling nanopores, which allow the penetration of corrosive media toward the base aluminum. We designed a mixed sealing solution with nickel acetate and ammonium fluoride by modifying traditional nickel fluoride cold sealing. The concentration of mixed sealing solution affected the reaction rate of sealing and corrosion current density of anodized aluminum alloy. The higher concentration of mixed sealing solution improved the sealing rate, which was represented by a decrease of corrosion current density of anodized aluminum alloy. However, a mixed sealing solution with 2/3 concentration of general nickel fluoride sealing solution operated at room temperature showed the lowest corrosion current density compared to traditional methods (e.g., nickel fluoride cold sealing (NFCS) and nickel acetate hot sealing) and other mixed sealing solutions. Moreover, the mixed sealing solution with 2/3 concentration of general NFCS had a lower risk for over sealing, which increases the corrosion current density by excessive dissolution of anodic oxide. Therefore, the mixed sealing solution with optimized conditions designed in this work possibly provides a new method for enhancing the corrosion resistance of anodized aluminum alloys.

Surface Treatments of Stainless Steel by Electroless Silver Coatings as a Bipolar Plate for Proton Exchange Membrane Fuel Cells

2015 ◽  
Vol 12 (6) ◽  
Author(s):  
Ing-Bang Huang ◽  
Ching Chiang Hwang
Keyword(s):  
Corrosion Resistance ◽  
Fuel Cell ◽  
Current Density ◽  
Corrosion Current Density ◽  
Proton Exchange Membrane ◽  
Corrosion Current ◽  
Proton Exchange ◽  
Heat Treated Sample ◽  
Heat Treated ◽  
Exchange Membrane

The objective of this study is to examine the effect of heat treatment at various temperatures on the corrosion behavior of electroless silver-coated SS 304 in a simulated proton exchange membrane (PEM) fuel cell environment. The corrosion properties of this material were studied using a potentiodynamic polarization technique. X-ray diffraction (XRD) patterns, polarization curves, and scanning electron microscopy (SEM) of coated and heat-treated specimens obtained in various heating temperatures were also utilized. It was found that the corrosion potential of the coated and heat-treated specimens shift toward a noble potential, and a significant decrease in corrosion current density was also observed. The corrosion current density decreased by a factor of about 1/500 for the heat-treated sample of 600 °C compared to the substrate. The heat-treated specimens displayed greater corrosion resistance than unheated and bare ones. According to the polarization studies and SEM images, the heat-treated specimen at 600 °C shows excellent corrosion resistance with a homogeneous dense surface morphology. These results demonstrated the coatings were suited for fuel cell applications in the proton exchange membrane fuel cell (PEMFC) environment.

Protective behavior of volatile corrosion inhibitor on atmospheric corrosion process of carbon steel under thin electrolyte liquid film of chloride solutions

2020 ◽  
Vol 10 (9) ◽  
pp. 1435-1443
Author(s):  
Dong Wang ◽  
Chenxi Wang ◽  
Changqing Fang ◽  
Xing Zhou ◽  
Mengyuan Pu ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Carbon Steel ◽  
Liquid Film ◽  
Corrosion Inhibitor ◽  
Current Density ◽  
Atmospheric Corrosion ◽  
Corrosion Current Density ◽  
Corrosion Current ◽  
Corrosion Process ◽  
Closed Container

The corrosion process of carbon steel and corrosion resistance behavior of volatile corrosion inhibitor (VCI) under thin electrolyte liquid film containing chloride was investigated by electrochemical measurements and surface characterization. Results indicated that composite VCI was composed of sodium molybdate and sodium benzoate, and exhibited higher corrosion resistance in 3.5% NaCl solution compared with absence of VCI. The corrosion current density obviously decreased with presence of VCI, and the synergies between binary components increased the corrosion inhibiting rate on carbon steel to up to 90%. The corrosion current density of carbon steel increased with increased temperature after volatilization of VCI. A closed container was carried out to mimic atmospheric corrosion condition, and its vapor corrosion inhibition property was evaluated in this closed container. Results showed that the VCI acted as an inhibitor by suppressing anodic dissolution and metallic ion transfer through the formation of protective film. It was also observed that the variation of carbon steel surface with volatilization of VCI was assessed by atomic force microscope (AFM) and scanning electron microscope (SEM). The anodic process for carbon steel without VCI affected the corrosion rate due to accumulation of corrosion products, while the morphology of carbon steel was hardly changed with volatilization of VCI. The results showed that the VCI volatilized to the surface and form to protect film. VCI was automatically volatilized into gas, which protected steel from corrosion. This composite VCI can then be applied as a significant corrosion inhibition method.

Corrosion Behavior of the Transient Liquid Phase Diffusion Bonding Joint of TiNi Shape Memory Alloy and Stainless Steel in Hanks' Solution

2013 ◽  
Vol 750-752 ◽  
pp. 739-742
Author(s):  
Ying Ling Wang ◽  
Qiu Zhi Gao ◽  
Gui Fang Sun ◽  
Jie Ye
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Liquid Phase ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Corrosion Behavior ◽  
Pitting Corrosion ◽  
Diffusion Bonding ◽  
Transient Liquid Phase ◽  
Phase Diffusion

The transient liquid phase diffusion bonding (TLP-DB) was employed to join TiNi shape memory alloy (SMA) and stainless steel (SS) with an interlayer metal of Ag-Cu eutectic metal foil.The corrosion behavior of the TLP-DB joint in Hanks solution at 37°C was investigated by electrochemical methods.The results show that the corrosion resistance of the joint is comparable to, but lower than that of base metals during the early anodic polarization, and the corrosion rate of the joint is between that of TiNi SMA and SS in the transpassive region at high potentials. The corrosion resistance of the specimens in Hanks' solution is associated with the surface quality, mircotructure and the intermetallics. Both TiNi SMA and SS display the characteristics of localized corrosion with a little pitting corrosion, while the joints mainly show the characteristics of pitting corrosion concentrated on the enrichment Cu phases.

Corrosion Resistance of Mg-4Zn Alloy with Amorphous Micro-Arc Oxidation Coating in Simulated Body Fluid

2016 ◽  
Vol 852 ◽  
pp. 1325-1333
Author(s):  
Li Chen Zhao ◽  
Shuang Jin Liu ◽  
Yu Min Qi ◽  
Chun Xiang Cui
Keyword(s):  
Corrosion Resistance ◽  
Simulated Body Fluid ◽  
Current Density ◽  
Polarization Resistance ◽  
Body Fluid ◽  
Corrosion Current Density ◽  
Corrosion Current ◽  
Metal Substrate ◽  
Electrochemical Measurements ◽  
Micro Arc Oxidation

A binary Mg-4Zn alloy was fabricated as a potential degradable biomaterial. To improve the corrosion resistance of Mg-4Zn alloy, an amorphous micro-arc oxidation (MAO) coating was prepared on the Mg-4Zn substrate. Electrochemical measurements and immersion tests were employed to evaluate the corrosion resistance of the specimen in simulated body fluid (SBF). Electrochemical measurements show that the Mg-4Zn alloy covered with a MAO coating has a much lower corrosion current density and a much greater polarization resistance. Immersion tests suggest that the degradation of Mg-4Zn substrate is relatively serious during the initial 8 h of immersion although it has been protected by a MAO coating. When most micro-pores within the MAO coating have been filled with precipitates resulted from the corrosion of the metal substrate, the degradation of the Mg-4Zn substrate is significantly delayed.

Sign in / Sign up

Export Citation Format

Share Document