scholarly journals Corrosion Resistance of Electroless Ni-Cu-P Ternary Alloy Coatings in Acidic and Neutral Corrosive Mediums

2010 ◽  
Vol 2010 ◽  
pp. 1-9 ◽  
Author(s):  
Mbouillé Cissé ◽  
Mohamed Abouchane ◽  
Tayeb Anik ◽  
Karima Himm ◽  
Rida Allah Belakhmima ◽  
...  

Electroless Ni-Cu-P alloy coatings were deposited on the ordinary steel substrate in an acidic hypophosphite-type plating bath. These coatings were characterized by a scanning electron microscope (SEM) and an X-ray diffraction. The micrograph shows that coating presents a nodular aspect and is relatively homogeneous and very smooth. The EDX analysis shows that the coating contains 12 wt.% of phosphorus element with a predominance of nickel element. In addition, the anticorrosion properties of the Ni-Cu-P coatings in 1 M HCl, 1 M H2SO4, and 3% NaCl solutions were investigated using Tafel polarization curves, electrochemical impedance spectroscopy, and SEM/EDX analysis. The result showed a marginal improvement in corrosion resistance in 3% NaCl solution compared to acidic medium. It also showed that the corrosion mechanism depends on the nature of the solution.

2008 ◽  
Vol 22 (18n19) ◽  
pp. 3031-3036 ◽  
Author(s):  
FARYAD BIGDELI ◽  
SAEED REZA ALLAHKARAM

Composite coatings constitute a new class of materials which are mostly used for mechanical and tribological applications. The corrosion resistance of these composite coatings, however, has not been systematically studied and compared. In this study, electroless Ni – P composite coatings are formed on St 37 steel through the addition of nano-scale SiC particles to the plating bath. This work aimed to investigate the corrosion characteristics of electroless nickel composite coatings using electrochemical measurements which include polarization and electrochemical impedance spectroscopy tests. The morphology and structure of the composite coatings were studied by scanning electron microscopy (SEM), energy dispersive spectrum (EDS) and X-ray diffraction (XRD). The results showed that both electroless nickel and electroless nickel composite coatings demonstrated significant improvement of corrosion resistance in salty atmosphere.


2020 ◽  
Vol 32 (6) ◽  
pp. 1384-1392
Author(s):  
N. M'hanni ◽  
M. Galai ◽  
T. Anik ◽  
M. Ebn Touhami ◽  
E.H. Rifi ◽  
...  

The autocatalytic nickel bath uses sodium hypophosphite as a reducing agent, sodium citrate as a complexing agent and sodium acetate as an accelerator. The effect of calix[4]arene molecule type H4L named (dicarboxylic acid p-tert-butylcalix[4]arene) was studied and used at various concentrations of 10-3 to 10-6 M to improve the microstructure, the microhadness and properties of nickel deposit obtained. The effect of varying the concentration of H4L, on the deposition rate, the composition, the microstructure and morphology of chemical deposition was studied. The results showed that depending on the concentration of calix[4]arene, the deposition rate decreases from 11, to 7.75 μm/h. The microstructure and microhardness improves significantly at a concentration of 10-6 M of additive. It was also shown that the coating obtained is adherent and compact and the chemical bath has become more stable in the presence of calix[4]arenic additives. Indeed, in both cases, the nickel content decreased with the addition of concentration. This decrease of nickel content might be related to the increase of deposition rate depending on the concentration. The X-ray diffraction analysis revealed peak intensification in the {111} orientation of plane in the presence of a concentration of 10-6 M; this may be in agreement with the results of metallographic study which showed that the coatings are adherent and have a good resistance. Hence, the Vickers microhardness of deposited coatings has a better value (376 HV) at the concentration 10-6 M. The corrosion resistance in 3% NaCl solution has been proven at the same concentration as found. Finally, the cyclic voltammetry and electrochemical impedance spectroscopic studies revealed that the additive strongly influences the cathodic process and affects slightly oxidation of hypophosphite.


2011 ◽  
Vol 399-401 ◽  
pp. 2055-2060
Author(s):  
Ji Bo Jiang ◽  
Wei Dong Liu ◽  
Lei Zhang ◽  
Qing Dong Zhong ◽  
Yi Wang ◽  
...  

Ni–B4C composite coatings on carbon steel substrates with various contents of B4C nano-particulates were prepared by electrodeposition in Ni plating bath containing B4C nano-particulates. Microhardness, Scanning Electron Microscopy (SEM), Tafel polarization and Electrochemical Impedance Spectroscopy (EIS) measurements were used to compare pure nickel coatings and Ni–B4C composite coatings. Pure Ni coating microhardness is lower than that of Ni–B4C coatings and the microhardness of the composite coatings increases with the increase of the content of B4C nano-particulates. The effects of various contents of B4C nano-particulates on the corrosion resistance were investigated and it was found that the best anti–corrosion property of Ni–B4C composite coatings is at 6 g/L B4C in the bath formulation.


2016 ◽  
Vol 23 (3) ◽  
pp. 309-314
Author(s):  
M. Edwin Sahayaraj ◽  
J.T. Winowlin Jappes ◽  
I. Siva ◽  
N. Rajini

AbstractElectroless nickel coating treatment improves the corrosion resistance of mild steel. This work aims at studying the corrosion behavior of electroless Ni-P/TiO2 composite and multilayer coatings applied to the mild steel substrate as their as-plated state and furnace annealed at various temperatures and compared both the coatings’ corrosion performance. The corrosion behavior of the deposits was evaluated by potentiodynamic polarization studies in 3.5 wt% sodium chloride solution. The results showed that the corrosion resistance of the multilayer coating was two times higher compared to the composite coatings. Further, the corrosion mechanism was discussed in terms of microstructure, phase transformation, grain size, and microstrain.


2013 ◽  
Vol 738 ◽  
pp. 87-91 ◽  
Author(s):  
Jin Ming Long ◽  
Xiu Zhang ◽  
He Zhong Pei

Zn-Ni alloy coatings were electrodeposited on low carbon steel substrate using a cyanide-free alkaline bath containing tetraethylenepentamine (TEPA) and triethanolamine (TEA) as complexing agents for Ni2+cations. Effect of TEA/Ni2+molar ratio on electrodeposition behavior, micromophology, Ni content and corrosion resistance of coatings were studied by means of SEM/EDS, polarization curve and electrochemical impedance spectroscopy (EIS), respectively. It was found that the deposition potential and elecctrochemical impedance of the cathode sample during the electrodeposition was influenced by the TEA/Ni2+molar ratio (TNmr) in the bath. The deposition potential shifts negatively and the impedance rises with increasing TNmrup to 2. The nickel content in Zn-Ni deposit was varied in a range from 16.81 to 19.04 wt.%. The dependence of cathodic current efficiency and depositing velocity of the coating on TNmrof plating bath were also determined. A fine-grained and smooth-faced coating was obtained at TNmr=2, which exhibited the highest corrosion resistance in 3.5% NaCl environment.


2012 ◽  
Vol 05 ◽  
pp. 817-824 ◽  
Author(s):  
S.R. Allahkaram ◽  
A. Zarebidaki ◽  
T. Rabizadeh

SiC and SiO 2 nano-particles were co-deposited with electroless NiP coating onto API-5L-X65 steel substrates with 7g/L load of nano-particles in the bath at pH 4.6 ± 0.2 and temperature of 90 ± 2°C. The hardness and corrosion resistance of the composite coatings were measured using micro-hardness, polarization and electrochemical impedance spectroscopy techniques, respectively. Moreover, the structure of the composite coatings was investigated by means of X-ray diffraction (XRD) technique, while their morphologies and elemental compositions were analyzed using a scanning electron microscope (SEM) equipped with an energy dispersive spectrometer (EDS). Results showed that co-deposited nano-particles caused an increase in the hardness of the composite coatings. Corrosion tests showed that addition of nano- SiO 2 particles improved corrosion resistance of electroless Ni - P coatings in salty atmosphere but addition of nano- SiC particles decreased, due to the agglomeration of SiC nano-particles together with an increase in the porosity of the composite coatings.


2015 ◽  
Vol 761 ◽  
pp. 407-411 ◽  
Author(s):  
Muhammad Zaimi ◽  
Mohd Asyadi Azam ◽  
Azizul Helmi Sofian ◽  
Kazuhiko Noda

Zinc and copper addition into electroless Ni-P alloy matrix produces quaternary Ni alloy that exhibits lower corrosion resistance behavior compared to Ni-P and Ni-Cu-P alloy in 3.5 wt% NaCl solution. The corrosion behavior of the alloy is previously studied using the anodic polarization curve measurement. The results show that the corrosion potential of different alloy composition is almost similar to each other for electroless Ni-Zn-Cu-P alloy. However, the surface resistance of the alloy needs to be confirmed by using electrochemical impedance spectroscopy. The alloy was first deposited on an iron substrate using electroless Ni alloy deposition method approximately similar thickness at different plating bath pH of 8.50 and 9.50. The Ni alloy coated substrate was used as working electrode immersed into a solution of 3.5 wt% NaCl. The electrochemical cell consists of Pt and Ag/AgCl/KCl (saturated) as counter and reference electrode respectively. Electrochemical impedance measurement was done at open circuit potential. The measurement started from 100 kHz to 10 mHz with 10 mV of sinusoidal perturbation applied to the cell. Other types of alloy including Ni-P, Ni-Cu-P and Ni-Zn-P, were compared with Ni-Zn-Cu-P alloy. From the results, the Ni-Zn-Cu-P exhibits the lowest corrosion behavior compared to other Ni alloy due to low charge transfer resistance (Rct) observed small inductive loop at low frequency region of the Nyquist plot. Furthermore, the Nyquist plot for Ni-Zn-Cu-P for pH 8.50 and 9.50 showed comparable result; hence, the effect of pH has less effect on corrosion resistance of the electroless Ni-Zn-Cu-P alloy.


2014 ◽  
Vol 599-601 ◽  
pp. 40-43
Author(s):  
Xia Zhao ◽  
Shuan Liu ◽  
Bao Rong Hou

Corrosion resistance of X52 pipeline steel at sea mud zone in Qingdao Huiquan test station was investigated by using Tafel polarization curves and electrochemical impedance spectroscopy (EIS). The morphology and chemical composition of the corrosion products were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results indicated that the corrosion current density of X52 pipeline steel increased with immersion time. The corrosion products were loose and mainly included Fe3O4, Fe2O3 and FeOCl, which absorbed on the specimen surface accelerating the cathodic depolarization reaction.


Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 852
Author(s):  
Asiful H. Seikh ◽  
Hossam Halfa ◽  
Mahmoud S. Soliman

Molybdenum (Mo) is an important alloying element in maraging steels. In this study, we altered the Mo concentration during the production of four cobalt-free maraging steels using an electroslag refining process. The microstructure of the four forged maraging steels was evaluated to examine phase contents by optical microscopy, scanning electron microscopy (SEM), and X-ray diffraction (XRD) analysis. Additionally, we assessed the corrosion resistance of the newly developed alloys in 3.5% NaCl solution and 1 M H2SO4 solution through potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. Furthermore, we performed SEM and energy-dispersive spectroscopy (EDS) analysis after corrosion to assess changes in microstructure and Raman spectroscopy to identify the presence of phases on the electrode surface. The microstructural analysis shows that the formation of retained austenite increases with increasing Mo concentrations. It is found from corrosion study that increasing Mo concentration up to 4.6% increased the corrosion resistance of the steel. However, further increase in Mo concentration reduces the corrosion resistance.


2022 ◽  
Vol 1048 ◽  
pp. 72-79
Author(s):  
Suriaya Hassan ◽  
Abdul Ansari ◽  
Arvind Kumar ◽  
Munna Ram ◽  
Sulaxna Sharma ◽  
...  

In current investigation, the Ni-P-W/ZrO2 electroless nanocomposite coatings are deposited upon mild steel substrate (AISI 1040 grade). The W/ZrO2 nanoparticles (50 to 130 nm range) were incorporated separately into acidic electroless Ni-P matrix as a second phase materials. The as-plated EL Ni-P-W/ZrO2 depositions were also heated at 400 οC in Argon atmosphere for one hour duration and analyzed by SEM/EDAX and XRD physical methods. The Ni-P-W/ZrO2 as-plated coupons revealed nebulous type structures while heated coupons showed crystalline structures in both cases. Furthermore Ni-P-ZrO2 coatings have very less cracks and gaps as compared to Ni-P-W coatings. The corrosion tests result in peracid (0.30 ± 0.02 % active oxygen) solutions point up that corrosivity of peracid ( 500 ppm Cl) is more than peracid (0 ppm Cl) and corrosion resistance of tested coupons varies as Ni-P-ZrO2 (as-plated) > Ni-P-ZrO2 (heated) > Ni-P-W (as-plated) > Ni-P-W (heated) > MS. The utilization of Ni-P-ZrO2 nanocomposite coatings in peracid solutions can be considered a cost effective option on the basis of its better cost/strength ratio in addition to its fair corrosion resistance.


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