scholarly journals Role of the newly synthesized brightener in modification of surface properties of Zn-Ni alloy electrodeposited on steel substrate

2019 ◽  
Vol 9 (3) ◽  
pp. 175-185
Author(s):  
Jyoti S. Kavirajwar ◽  
Basavanna Shivarudraiah ◽  
Yanjerappa Arthoba Nayaka
Keyword(s):  
Steel Substrate ◽  
Alloy Coating ◽  
Xrd Analysis ◽  
Nucleation Mechanism ◽  
Spectroscopic Techniques ◽  
Alloy Electrodeposition ◽  
Corrosion Studies ◽  
Cysteine Hydrochloride ◽  
Ni Alloy

In the present study, a new brightener was synthesized by condensation of salicylaldehyde and cysteine hydrochloride (SC). To examine the influence of SC on the nucleation mechanism of Zn-Ni alloy, electrodeposition, cyclic voltammetric and chronoamperometric studies were carried out. The model of Schariffker and Hills was used to analyze current transients which explained the electrocrystallization process of Zn-Ni alloy. It is revealed that Zn-Ni electrocrystallization process in presence of SC is regulated by instantaneous nucleation mechanism. The corrosion studies were done for the bright and dull zinc-nickel alloy coatings in 3.5 wt.% NaCl solution, using potentiodynamic polarization and electro­chemical impedance spectroscopic techniques. The phase structure, surface morphology and brightness of the deposit were characterized by means of X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM) and reflectance studies. These studies revealed the role of SC in producing a bright Zn-Ni alloy coating on mild steel substrate and also showed its improved corrosion resistant nature.

Effect of Doping of Nanoparticles on the Properties of Zn-Ni Composite Coatings

2018 ◽  
Vol 18 ◽  
pp. 19-26
Author(s):  
Nadjette Belhamra ◽  
Abd Raouf Boulebtina ◽  
Khadidja Belassadi ◽  
Abdelouahed Chala ◽  
Malika Diafi
Keyword(s):  
Corrosion Resistance ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Steel Substrate ◽  
Composite Coatings ◽  
Alloy Coating ◽  
Corrosion Performance ◽  
X Ray ◽  
Ni Alloy

The purpose of this paper was to investigate the effect of Al2O3 and TiO2 nanoparticles contents on structural proporties, microhardness and corrosion resistance of Zn-Ni alloy coationg. Zn-Ni, Zn-Ni-Al2O3 and Zn-Ni-TiO2 composite coatings were electrodeposited on steel substrate by direct current in sulphate bath.The structure of the coatings was studied by X-ray diffration and by scaning electron miroscopy. The results showed the appearance of Ni5Zn21 phases and that the incrorporation of Al2O3 and TiO2 in the Zn-Ni coating refined the crystal grain size.The corrosion performance of coating in the 0.6M NaCl as a corrisive solution was investigated by potentiodynamic polarization and electrochemical impedance spectroscopy EIS methods. It was found that the incorporation of nanoparticules in Zn-Ni alloy coating have better corrosion resistance and the values of Rct and Zw increase, while the values of Cdl decrease with increasing of nanoparticules.

scholarly journals Effect of heat treatment on the tribological performance of electroless quaternary nickel alloy

2019 ◽  
Vol 13 (3) ◽  
pp. 5637-5652
Author(s):  
M. Zaimi ◽  
M. N. Azran ◽  
M. S. Kasim ◽  
M. R. M. Kamal ◽  
I. S. Othman ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Wear Behavior ◽  
Steel Substrate ◽  
Alloy Coating ◽  
Xrd Analysis ◽  
Alloy Matrix ◽  
X Ray ◽  
Hardness Tester ◽  
Heat Treated ◽  
Before And After

Heat treatment of nickel-based alloy can increase the alloy’s hardness as well as the wear resistance properties. Nevertheless, the effect of heat treatment on the quaternary Ni alloy coating properties produced from electroless deposition bath is less known due to its composition uniqueness. In this study, Cu and Co are added in the Ni-P alloy matrix using hypophosphite-based Electroless Ni deposition method on mild steel substrate in acidic and alkaline bath. The coatings are then heat treated at 623 K for 3600s. The coatings hardness is measured using microVickers hardness tester and the surface morphology of the coatings are studied using both Scanning Electron Microscope (SEM) and X-ray diffraction (XRD) analysis. X-ray fluorescence (XRF) measurement is used to measure the coatings compositions. The wear behavior of the coatings is also investigated before and after heat treatment using ASTM G-99. The coatings from acidic-based bath produces Ni-Cu-Co-P alloy coating while the alkaline-based bath produces Ni-Co-Cu-P alloy based on XRF analysis. Results show that the hardness increases more than 20% for acidic-based bath and 40% for alkaline-based bath coating. The highest increment is the Ni-Co-Cu-P alloy, from 553.3 HV to 991.3 HV after heat treatment. The grain refinement of the coatings can be observed after heat treatment in SEM observation. This is proved by the XRD measurement results where polycrystalline Ni (111) formation is seen after heat treatment overshadowing the Cu (111) and Co (111) peaks. Ni phosphide species are also formed after the heat treatment. The polycrystalline Ni and the Ni phosphide formation, as well as the existence of Co and Cu in the alloy deposits reduces the wear rate significantly after the heat treatment.

scholarly journals Effects of bath composition and current density on the electrodeposition of Fe-Ni alloy on copper substrate and the property of deposited alloy

2013 ◽  
Vol 47 (4) ◽  
pp. 379-386
Author(s):  
Md. Moniruzzaman ◽  
Md. Aminul Islam
Keyword(s):  
Current Density ◽  
Copper Substrate ◽  
Alloy Coating ◽  
Coarse Grained ◽  
Constant Current ◽  
Constant Current Density ◽  
Alloy Electrodeposition ◽  
Current Density Range ◽  
Ni Alloy ◽  
Anomalous Nature

One simple and six complex baths are used to electrodeposit Fe-Ni alloy coating on copper substrate. All baths contain the same 1.04 Ni/Fe ratio. In addition to NiSO4.7H2O, FeSO4.7H2O, H3BO3 used in simple bath, the complex baths contain Ascorbic acid, Saccharin and Citric acid in different ratios. Electrodepositions have been carried out in the bath pH and constant current density range of 1 - 2.6 and 20 - 140 mA/cm2, respectively. Anomalous nature of Fe-Ni alloy electrodeposition is suppressed in the complex baths. Microhardness as well as corrosion resistance of coating increased with increasing %Ni content in the deposit. The morphology of the Fe-Ni films obtained from simple baths is characterized by coarse-grained, non-smooth surface with presence of microcracks onto it. Coatings from complex baths are finegrained with smooth surfaces. Bangladesh J. Sci. Ind. Res. 47(4), 379-386, 2012 DOI: http://dx.doi.org/10.3329/bjsir.v47i4.8699

Microstructure, Corrosion and Wear Resistance of Co-Ni-ZrO2 Composite Coating

2015 ◽  
Vol 817 ◽  
pp. 449-453
Author(s):  
Jun Gao ◽  
Wan Chang Sun ◽  
Qin Shi ◽  
Ying Wang ◽  
Miao Miao Tian
Keyword(s):  
Wear Resistance ◽  
Composite Coating ◽  
Steel Substrate ◽  
Composite Coatings ◽  
Alloy Coating ◽  
Corrosion And Wear ◽  
Submicron Particles ◽  
Electrolytic Deposition ◽  
Wear Loss ◽  
Ni Alloy

Co-Ni alloy and ZrO2 submicron particles were successfully co-deposited on carbon steel substrate by direct current electrolytic deposition. The micromorphology, constituent, microhardness, corrosion and wear resistance of the composite coatings were tested, respectively. The results show that the embedded submicron ZrO2 particles are uniformly distributed in the entire Co-Ni matrix and the coating showed a good adhesion to the substrate. The hardness, friction coefficient, wear loss, and electrode voltage of Co-Ni alloy coating were 356 HV, 0.8, 1.901×10-2 mg/m, and-0.47 V, respectively, while those of Co-Ni-ZrO2 composite coating were 413 HV, 0.6, 1.174×10-2 mg/m, and-0.37 V, respectively. The data above suggested that Co-Ni-ZrO2 composite coating possesses higher microhardness, better wear and corrosion resistance.

Anodic Treatment of Zn-Ni Alloy in Alkaline Solutions

2015 ◽  
Vol 227 ◽  
pp. 139-142 ◽  
Author(s):  
Artur Maciej ◽  
Joanna Michalska ◽  
Wojciech Simka ◽  
Maciej Sowa ◽  
Tadeusz Gorewoda ◽  
...  
Keyword(s):  
Surface Morphology ◽  
Sodium Hydroxide ◽  
Sodium Silicate ◽  
Main Part ◽  
Alloy Coating ◽  
Alkaline Solutions ◽  
Anodic Treatment ◽  
Corrosion Studies ◽  
Alkali Solutions ◽  
Ni Alloy

The investigations on anodic oxidation of galvanic Zn-Ni alloy coating in the baths containing sodium hydroxide, sodium silicate and ammonium pentaborate was described in this paper. The surface morphology studies (SEM) and corrosion characterization was the main part of the work. It was found that the anodic treatment of the Zn-Ni alloy coating in the alkali solutions basis on NaOH permit to the obtaining the oxide layer with cracks formation. Application of the baths containing also sodium silicate and ammonium pentaborate cause the cracks decay. The corrosion studies may indicate that the cracks are shallow.

scholarly journals Effect of Ni Concentration on the Surface Morphology and Corrosion Behavior of Zn-Ni Alloy Coatings

Metals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 96
Author(s):  
Ameeq Farooq ◽  
Sohaib Ahmad ◽  
Kotiba Hamad ◽  
Kashif Mairaj Deen
Keyword(s):  
Surface Morphology ◽  
Coating Thickness ◽  
Steel Substrate ◽  
Salt Spray ◽  
Research Work ◽  
Alloy Coating ◽  
Open Circuit ◽  
Dissolution Behavior ◽  
Cyclic Polarization ◽  
Ni Alloy

This research work aims to develop electrodeposited Zn-Ni alloy coatings with controlled dissolution tendencies on a mild steel substrate. The varying Ni concentration in the electroplating bath, i.e., 10, 15, 20 and 25 g·L−1, affected the surface morphology and electrochemical properties of the deposited Zn-Ni alloy coatings. SEM and EDS analysis revealed the resulting variation in surface morphology and composition. The electrochemical behavior of different coatings was evaluated by measuring the open circuit potential and cyclic polarization trends in 3.5 wt.% NaCl solution. The degradation behavior of the electrodeposited Zn-Ni coatings was estimated by conducting a salt spray test for 96 h. The addition of Ni in the coating influenced the coating thickness and surface morphology of the coatings. The coating thickness decreased from 38.2 ± 0.5 μm to 20.7 ± 0.5 μm with the increase in Ni concentration. Relatively negative corrosion potential (<−1074 ± 10 mV) of the Zn-Ni alloy coatings compared to the steel substrate (−969 mV) indicated the sacrificial dissolution behavior of the Zn-rich coatings. On the other hand, compared to the pure Zn (26.12 mpy), ~4 times lower corrosion rate of the Zn-Ni coating (7.85 mpy) was observed by the addition of 25 g·L−1 Ni+2 in the bath solution. These results highlighted that the dissolution rate of the sacrificial Zn-Ni alloy coatings can effectively be tuned by the addition of Ni in the alloy coating during the electrodeposition process.

Key Role of the Oxidized Citrate-Free Radical in the Nucleation Mechanism of the Metal Nanoparticle Turkevich Synthesis

2019 ◽  
Vol 123 (36) ◽  
pp. 22624-22633 ◽  
Author(s):  
Sarah Al Gharib ◽  
Jean-Louis Marignier ◽  
Abdel Karim El Omar ◽  
Adnan Naja ◽  
Sophie Le Caer ◽  
...  
Keyword(s):  
Free Radical ◽  
Nucleation Mechanism ◽  
Metal Nanoparticle

scholarly journals Yttrium doped phosphate-based glasses: structural and degradation analyses

2020 ◽  
Vol 6 (1) ◽  
pp. 34-49
Author(s):  
Abul Arafat ◽  
Sabrin A. Samad ◽  
Jeremy J. Titman ◽  
Andrew L. Lewis ◽  
Emma R. Barney ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Structural Changes ◽  
Xrd Analysis ◽  
Calcium Pyrophosphate ◽  
Ion Release ◽  
Subsequent Increase ◽  
Structural Characterisation ◽  
Release Studies ◽  
Degradation Properties

AbstractThis study investigates the role of yttrium in phosphate-based glasses in the system 45(P2O5)–25(CaO)– (30-x)(Na2O)–x(Y2O3) (0≤x≤5) prepared via melt quenching and focuses on their structural characterisation and degradation properties. The structural analyses were performed using a combination of solid-state nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). 31P NMR analysis showed that depolymerisation of the phosphate network occurred which increased with Y2O3 content as metaphosphate units (Q2) decreased with subsequent increase in pyrophosphate species (Q1). The NMR results correlated well with structural changes observed via FTIR and XPS analyses. XRD analysis of crystallised glass samples revealed the presence of calcium pyrophosphate (Ca2P2O7) and sodium metaphosphate (NaPO3) phases for all the glass formulations explored. Yttrium-containing phases were found for the formulations containing 3 and 5 mol% Y2O3. Degradation analyses performed in Phosphate buffer saline (PBS) and Milli-Q water revealed significantly reduced rates with addition of Y2O3 content. This decrease was attributed to the formation of Y-O-P bonds where the octahedral structure of yttrium (YO6) cross-linked phosphate chains, subsequently leading to an increase in chemical durability of the glasses. The ion release studies also showed good correlation with the degradation profiles.

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