Improved Corrosion Resistance and Increased Hardness of Copper Substrates from Cu-Ni/Ni-P Composite Coatings

MRS Advances ◽  
2020 ◽  
Vol 5 (40-41) ◽  
pp. 2129-2137 ◽  
Author(s):  
Wenwen Dou ◽  
Wen Li ◽  
Yuchen Cai ◽  
Mengyao Dong ◽  
Xiaojing Wang ◽  
...  

ABSTRACTTo improve the corrosion resistance and to increase the hardness of copper substrate in marine environment, the Cu-Ni/Ni-P composite coatings were prepared on the copper substrate using the galvanostatic electrolytic deposition method. The deposition current densities were explored to find the optimized deposition conditions for forming the composite coatings. Corrosion resistance properties were analyzed using the polarization curves and electrochemical impedance spectroscopy (EIS). Considering the corrosion resistance and hardness, the −20 mA/cm2 was selected to deposit Cu-Ni coatings on copper substrate and the −30 mA/cm2 was selected to deposit Ni-P coating on the Cu-Ni layer. The Cu-Ni/Ni-P composite coatings not only exhibited superior corrosion resistance compared to single Cu-Ni coating in 3.5 wt.% NaCl solution, but also showed much better mechanical properties than single Cu-Ni coating.

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 704
Author(s):  
Marija Riđošić ◽  
Nebojša D. Nikolić ◽  
Asier Salicio-Paz ◽  
Eva García-Lecina ◽  
Ljiljana S. Živković ◽  
...  

Electrodeposition and characterization of novel ceria-doped Zn-Co composite coatings was the main goal of this research. Electrodeposited composite coatings were compared to pure Zn-Co coatings obtained under the same conditions. The effect of two ceria sources, powder and home-made sol, on the morphology and corrosion resistance of the composite coatings was determined. During the electrodeposition process the plating solution was successfully agitated in an ultrasound bath. The source of the particles was found to influence the stability and dispersity of plating solutions. The application of ceria sol resulted in an increase of the ceria content in the resulting coating and favored the refinement from cauliflower-like morphology (Zn-Co) to uniform and compact coral-like structure (Zn-Co-CeO2 sol). The corrosion resistance of the composite coatings was enhanced compared to bare Zn-Co as evidenced by electrochemical impedance spectroscopy and scanning Kelvin probe results. Zn-Co doped with ceria particles originating from ceria sol exhibited superior corrosion resistance compared to Zn-Co-CeO2 (powder) coatings. The self-healing rate of artificial defect was calculated based on measured Volta potential difference for which Zn-Co-CeO2 (sol) coatings exhibited a self-healing rate of 73.28% in a chloride-rich environment.


2011 ◽  
Vol 299-300 ◽  
pp. 427-431
Author(s):  
Yun Li ◽  
Shi Zhi Shang ◽  
Ming Cheng ◽  
Liang Xu ◽  
Shi Hong Zhang

The corrosion behavior of Zr53.5Cu26.5Ni5Al12Ag3 bulk amorphous alloy in 3.5% NaCl solution was investigated by using potentiodynamic polarization experiments and electrochemical impedance spectroscopy (EIS). The results show that Zr53.5Cu26.5Ni5Al12Ag3 bulk amorphous alloy has the better corrosion resistance than its corresponding crystal alloy. During the bath in the 3.5% NaCl solution at 25°C, Zr53.5Cu26.5Ni5Al12Ag3 alloy has the lower corrosion current density than the corresponding crystal alloy. After 100h, the corrosion current densities of Zr53.5Cu26.5Ni5Al12Ag3 and the corresponding crystal alloy are 3.8415×10-8A/cm2 and 5.2827×10-7A/cm2, respectively. The results of EIS test indicate that Zr53.5Cu26.5Ni5Al12Ag3 bulk amorphous alloy has the excellent corrosion resistance because passive film with stable structure formed on the surface in 3.5% NaCl solution. With an increase in the immersion time, the passive film becomes thicker. It leads to impedance resistance and corrosion resistance decrease. The surface of Zr53.5Cu26.5Ni5Al12Ag3 bulk amorphous alloy in 3.5% NaCl solution for 100h was analyzed by SEM and EDS. The results show that the corrosive pitting can be found at both the amorphous alloy and the corresponding crystal alloy. However, the amorphous alloy has the better corrosive pitting resistance than the crystal one because the corrosion products formed by selective dissolving of Zr and Al elements. Moreover, the addition of Ag element helps to improve the corrosion resistance of the amorphous alloy greatly.


Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2307 ◽  
Author(s):  
Lu Hao ◽  
Guowei Lv ◽  
Yaqian Zhou ◽  
Kaiming Zhu ◽  
Mochen Dong ◽  
...  

Zinc is widely used in battery negative electrodes and steel coatings for automotive industries. The anti-corrosion property of zinc is the most important factor determining the performance and lifetime of the products. In this paper, both size-controlled poly N-(vinyl)pyrrole (PNVPY) nanoparticles and carbon black (CB) nanoparticles were compounded with poly (vinyl butyral) (PVB) binder developing a series of composite coatings covered on the zinc substrates using a spin-coating technique. The morphologies of the surface and cross section of the PNVPY/CB/PVB coatings indicate that the PNVPY and CB nanoparticles are uniformly distributed in the matrix. The corrosion resistance of the composite coatings was tested by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization in a 3.5% NaCl solution. It is found that the coating with 1.9 wt.% PNVPY and 2.3 wt.% CB nanoparticles shows a remarkably high resistance value (Rc) and corrosion protection efficiency (99.99%). Meanwhile, the immersion results also reveal its superior corrosion resistance. It is considered that the nanoscale dispersion of PNVPY and carbon in PVB matrix and the strong interface action between the nanoparticles and PVB result in the uniform microstructure of the composites which endues the superior corrosion properties of the coatings.


2020 ◽  
Vol 7 (5) ◽  
pp. 191943
Author(s):  
Hao Xu ◽  
Haijun Hu ◽  
Hongmei Wang ◽  
Yongjun Li ◽  
Yun Li

This study investigated the corrosion resistance of graphene/waterborne epoxy composite coatings in CO 2 -satarated NaCl solution. The coatings were prepared by dispersing graphene in waterborne epoxy with the addition of carboxymethylcellulose sodium. The structure and composition of the coatings were characterized by scanning electron microscopy, transmission electron microscopy, Fourier-transform infrared and Raman spectroscopies. The corrosion resistance of the composite coatings was investigated by potentiodynamic polarization measurements and electrochemical impedance spectroscopy. Composite coatings with more uniform surfaces and far fewer defects than blank waterborne epoxy coatings were obtained on 1020 steel. The 0.5 wt% graphene/waterborne epoxy composite coating exhibited a much lower corrosion rate and provided better water resistance properties and long-term protection than those of the blank epoxy coating in CO 2 -satarated NaCl solution.


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.


2013 ◽  
Vol 785-786 ◽  
pp. 872-876
Author(s):  
Yong Huang ◽  
Shu Guang Han ◽  
Ya Jing Yan ◽  
Xiao Feng Pang

This work elucidated corrosion resistance of the electrodeposited MgO/calcium phosphate (Ca-P/MgO) films on titanium (Ti). The microstructure, phase composition, and corrosion resistance of the films were studied. Results revealed that The Ca-P/MgO composite coatings were rough and inhomogeneous, the upper layer was floral-like crystals or flakes agglomerates morphology, and the lower layer was needle-like crystals which were mutually cross linked. The coating was very dense, and the content of Mg was about 0.3 wt%. Potentiodynamic polarization test manifested that the Ca-P/MgO-coated surface exhibited superior corrosion resistance than the bare titanium.


Author(s):  
Muddasir Nawaz ◽  
Sehrish Habib ◽  
Adnan Khan ◽  
Abdul Shakoor ◽  
Ramazan Kahraman

The use of organic coating for the metals has been widely being used to protect the surface against corrosion. Polymeric coating incorporated with Nanocontainers loaded with inhibitor and self-healing provides better corrosion resistance. Cellulose microfibers (CMFs) used as smart carriers were synthesized and loaded with dodecylamine (DOC)-inhibitor and polyethyleneimine (PEI)-both inhibitor and self-healing agents. Smart polymeric coatings were developed by mixing CMF/DOC and CMFs/PEI into the epoxy matrix. Reference coatings (that has only CMFs) were also prepared for a compersion. Scanning electron microscope (SEM), X-ray diffraction spectroscopy (XRD), Fourier transform infrared spectroscopy (FTIR) and thermal gravitational analysis (TGA) were used to confirm the loading of DOC and PEI onto the CMFs. UV-vis analysis indicates that the self-release of inhibitor from CMFs is sensitive to pH of the solution and the immersion time. Recovery of controlled surface damage confirms the decent self-healing ability of the prepared smart coatings is due to the efficient release of inhibitor (DOC) and self-healing agent (PEI) in the damaged area leading to the formation of a protective film. Electrochemical impedance spectroscopy (EIS) results demonstrate that corrosion resistance of the smart coating increases with an increase in immersion time which is due to the progressive release of inhibitors from CMFs in response to the pH change. Therefore, smart coatings demonstrate superior properties as compared to the reference coatings. The study reveals the polymeric composite coatings have potential to inhibit the corrosion of steel for oil and gas industry.


2006 ◽  
Vol 530-531 ◽  
pp. 111-116
Author(s):  
M.C.E. Bandeira ◽  
F.D. Prochnow ◽  
Isolda Costa ◽  
César V. Franco

Nd-Fe-B magnets present outstanding magnetic properties. However, due to their low corrosion resistance, their applications are limited to non-corrosive environments. Nowadays, significant efforts are underway to increase the corrosion resistance of these materials, through the use of coatings. Herein are presented the results of a study on the corrosion resistance of Nd-Fe-B magnets coated with polypyrrole (PPY). The electrochemical behavior of coated and uncoated magnets has been studied by Electrochemical Impedance spectroscopy (EIS) in synthetic saliva. The results were compared to previous investigations, which were carried out under similar conditions, in Na2SO4 and NaCl solutions. In sulphate solution, the corrosion resistance of the PPY-coated magnet was 3 times larger (1600 .cm2) than that of uncoated magnet (500 .cm2). In NaCl solution, however, the corrosion resistance of coated and uncoated magnets were very similar (250 .cm2). In synthetic saliva, both the uncoated and coated magnets presented good corrosion performance (1940 .cm2). Such behavior can be attributed to the phosphate ions in saliva, which play a role as corrosion inhibitor, producing phosphating, at least partially, of the magnet surface. The PPY-coated magnets presented a strong diffusional control from moderate to low frequencies, caused by the polypyrrole film. The thicker PPY film increased the corrosion resistance of the magnet in synthetic saliva.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Bekir Güney ◽  
Yusuf Dilay ◽  
Moses M. Solomon ◽  
Hüsnü Gerengi ◽  
Adem Özkan ◽  
...  

Abstract 30MnB5 boron alloyed steel surface is coated using different coating techniques, namely 60(Ni-15Cr-4.4Si-3.5Fe-3.2B 0.7C)-40(WC 12Co) metallic powder plasma spray, Fe-28Cr-5C-1Mn alloy wire arc spray, WC-10Co-4Cr (thick) powder high velocity oxy-fuel (HVOF), and WC-10Co-4Cr (fine) diamond jet HVOF. The microstructure of the crude steel sample consists of ferrite and pearlite matrices and iron carbide structures. The intermediate binders are well bonded to the substrate for all coated surfaces. The arc spray coated surface shows the formation of lamellae. The cross-section of HVOF and diamond jet HVOF coated surfaces indicates the formation of WC, W2C Cr, and W parent matrix carbide structures. The corrosion characteristic of the coated steel has been investigated in 3.5 wt.% NaCl solution using electrochemical impedance spectroscopy (EIS), scanning electron microscope (SEM), and energy dispersive X-ray spectroscopy (EDAX) techniques. The results reveal that the steel corroded in the medium despite the coatings. However, the extent of corrosion varies. HVOF coated sample demonstrated the highest corrosion resistance while arc spray coated sample exhibited the least. EDAX mapping reveals that the elements in the coatings corroded in the order of their standard electrode potential (SEP). Higher corrosion resistance of HVOF coated sample is linked to the low SEP of tungsten.


CORROSION ◽  
10.5006/3767 ◽  
2022 ◽  
Author(s):  
Malvika Karri ◽  
Amit Verma ◽  
J.B. Singh ◽  
Sunil Kumar Bonagani ◽  
U.K. Goutam

This work seeks to understand the underlying mechanism involved in passivity of Ni-Cr-Mo alloys in a less concentrated HCl solution (1M) by systematically varying contents of Cr and Mo solutes in model Ni-Cr-Mo alloys. Corrosion behaviour was evaluated based on potentiodynamic polarisation tests carried out in conjunction with electrochemical impedance and x-ray photoelectron spectroscopies of passive films that formed on alloys during their exposure to the HCl solution. Results have shown that an increase in Mo alone is not sufficient to improve the corrosion resistance of the alloys at lower concentrations of HCl. Optimum concentrations of Cr and Mo solutes have been found to be in the vicinity of ~17 wt.% Cr and ~19 wt.% Mo for superior corrosion resistance of the alloys. This was attributed to the protection of the Cr2O3 layer as a consequence of the enrichment of Mo6+ ions in the passive film in 1M HCl solution.


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