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.

scholarly journals Sacrificial Dissolution of Zinc Electroplated and Cold Galvanized Coated Steel in Saline and Soil Environments: A Comparison

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 744
Author(s):  
Ameeq Farooq ◽  
Umer Masood Chaudry ◽  
Ahsan Saleem ◽  
Kashif Mairaj Deen ◽  
Kotiba Hamad ◽  
...  
Keyword(s):  
Corrosion Rate ◽  
Electrochemical Impedance ◽  
Saline Soil ◽  
Steel Substrate ◽  
Salt Spray ◽  
Steel Structures ◽  
Open Circuit ◽  
Cyclic Polarization ◽  
Transfer Resistance ◽  
Soil Solutions

To protect steel structures, zinc coatings are mostly used as a sacrificial barrier. This research aims to estimate the dissolution tendency of the electroplated and zinc-rich cold galvanized (ZRCG) coatings of a controlled thickness (35 ± 1 μm) applied via brush and dip coating methods on the mild steel. To assess the corrosion behavior of these coated samples in 3.5% NaCl and 10% NaCl containing soil solutions, open circuit potential (OCP), cyclic polarization (CP), and electrochemical impedance spectroscopy (EIS) tests were performed. The more negative OCP and appreciably large corrosion rate of the electroplated and ZRCG coated samples in 3.5% NaCl solution highlighted the preferential dissolution of Zn coatings. However, in saline soil solution, the relatively positive OCP (>−850 mV vs. Cu/CuSO4) and lower corrosion rate of the electroplated and ZRCG coatings compared to the uncoated steel sample indicated their incapacity to protect the steel substrate. The CP scans of the zinc electroplated samples showed a positive hysteresis loop after 24 h of exposure in 3.5% NaCl and saline soil solutions attributing to the localized dissolution of the coating. Similarly, the appreciable decrease in the charge transfer resistance of the electroplated samples after 24 h of exposure corresponded to their accelerated dissolution. Compared to the localized dissolution of the electroplated and brush-coated samples, the dip-coated ZRCG samples exhibited uniform dissolution during the extended exposure (500 h) salt spray test.

Influence of Thermal Treatment on the Structure and the Corrosion Resistance of Zn-Ni Alloy Coatings

2013 ◽  
Vol 203-204 ◽  
pp. 224-227
Author(s):  
Magdalena Popczyk ◽  
Bożena Łosiewicz ◽  
Grzegorz Dercz ◽  
Agnieszka Smołka
Keyword(s):  
Corrosion Resistance ◽  
Thermal Treatment ◽  
Surface Morphology ◽  
Steel Substrate ◽  
Diffraction Method ◽  
Corrosion Current ◽  
Potential Method ◽  
Open Circuit ◽  
X Ray ◽  
Ni Alloy

Electrolytic Zn-Ni alloy coatings were obtained on the steel substrate under galvanostatic conditions, and then, subjected to thermal treatment in argon atmosphere. The influence of thermal treatment on the surface morphology, phase composition and corrosion resistance of the electrodeposited coatings has been studied. Surface morphology was examined using a scanning electron microscopy. Chemical composition was determined by a X-ray fluorescence spectroscopy. Structural studies were carried out using a X-ray diffraction method. Corrosion resistance tests were carried out in 3% NaCl solution using open circuit potential method and potentiodynamic measurements. It was found that after thermal treatment, the value of polarization resistance increases, the value of the corrosion current decreases, and the value of corrosion potential is shifted towards anodic potentials. This suggests a positive effect of thermal treatment of the Zn-Ni alloy coatings on their corrosion resistance.

scholarly journals Preparation of Sol-Gel Derived Anticorrosive Coating on Q235 Carbon Steel Substrate with Long-Term Corrosion Prevention Durability

Materials ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 1960 ◽  
Author(s):  
Yue Li ◽  
Chunchun Wu ◽  
Ming Xue ◽  
Jiawen Cai ◽  
Yi Huang ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Coating Thickness ◽  
Steel Substrate ◽  
Salt Spray ◽  
Sol Gel ◽  
Coating System ◽  
Barrier Effect ◽  
Corrosion Prevention ◽  
Q235 Carbon Steel ◽  
Layer Coating

Anticorrosive coatings prepared by sol-gel derived approaches have become an emergent research area in the field of corrosion prevention materials. Furthermore, enhanced coating thickness can greatly improve the barrier effect of the sol-gel coatings, thus influencing their service life in industrial applications. Here, we propose the preparation of a two-layer coating system using a low-cost sol-gel derived method. The coating structure was composed of first an underlying layer incorporated with silica and titania powder as filler and pigment materials, and a second translucent topcoat containing a colloidal silica sol-gel matrix crosslinked by methyltrimethoxysilane (MTMS). This coating system was applied on Q235 carbon steel substrate by a two-step spray deposition method, resulting in an enhanced coating thickness of around 35 μm. The physical and morphological properties of the coatings were characterized using multiple techniques, including scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and atomic force microscopy (AFM). The anticorrosion performance of the sol-gel coatings was studied by a salt spray test, outdoor exposure test and electrochemical impedance spectroscopy (EIS). Results revealed that this two-layer coating system exhibited excellent physical and anticorrosion properties, and that the topcoat played a crucial role in maintaining the barrier effect and preventing water leakage.

Development of Corrosion Resistance Coating for AISI 410 Grade Steel

2015 ◽  
Vol 813-814 ◽  
pp. 135-139 ◽  
Author(s):  
K.G. Girisha ◽  
R. Rakesh ◽  
C. Durga Prasad ◽  
K.V. Sreenivas Rao
Keyword(s):  
Corrosion Resistance ◽  
Plasma Spray ◽  
Corrosion Behaviour ◽  
Steel Substrate ◽  
Salt Spray ◽  
Research Work ◽  
Optical Microscope ◽  
Air Plasma ◽  
Spray Process ◽  
Plasma Spray Process

In this present research work, corrosion behaviour of grit blasted AISI 410 steel substrate coated with NiCr/Al2O3,NiCr/ZrO2 particles was investigated using salt spray test as per ASTM B117. Coatings were prepared using air Plasma spray process. Nickel chromium was used as bond coat for obtaining good fastening between the base metal and coated particles. The microstructures of the coated and un-coated specimens were characterized using scanning electron microscope and optical microscope. Distribution coated particle was found uniform throughout the steel substrate was revealed from SEM microphotographs. The obtained results shows significant improvement in corrosion resistance and micro hardness for NiCr/Al2O3 and NiCr/ZrO2 coating deposited on steel by plasma spray process than the as sprayed base steel substrates.

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.

Galvanic Formation of Zn-Ni/Zn-Co Type Multilayer Alloy Coatings on Steel Substrate

2015 ◽  
Vol 227 ◽  
pp. 147-150
Author(s):  
Agnieszka Nagrabia ◽  
Maciej Sowa ◽  
Wojciech Simka ◽  
Artur Maciej
Keyword(s):  
Corrosion Resistance ◽  
Surface Layer ◽  
Steel Substrate ◽  
Salt Spray ◽  
Open Circuit ◽  
Neutral Salt ◽  
Weight Changes ◽  
Corrosion Properties ◽  
Potential Measurement ◽  
Layer Coating

Zn-Ni and Zn-Co monolayer and Zn-Ni/Zn-Co multilayer (from 2 to 128 layers) alloy coatings were formed on steel substrate by electrodeposition from acidic Zn-Ni bath and neutral Zn-Co bath. Samples were tested in salt chamber for corrosion resistance in neutral salt spray. Open circuit potential measurement and gravimetric study of corrosion were carried for samples immersed in the 5% NaCl solution.It was found that coatings of Zn-Ni surface layer occurred higher corrosion resistance then the coatings of Zn-Co surface layer. Sixteen-layer coating with Zn-Ni surface layer proved to be most effective in protecting the steel substrate. Zn-Ni monolayer showed the lowest corrosion potential, which affects the corrosion properties. Sample weight changes during exposure to a corrosive environment are related to digestion of the coating and the formation of corrosion products.

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.

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.

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.

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