scholarly journals Effect of Additives on Electrodeposition of Zinc-Nickel Alloy On Mild Steel

2019 ◽  
Vol 31 (4) ◽  
pp. 891-895
Author(s):  
Dinesh Kumar Chelike ◽  
K. Juliet Gnana Sundari

Considering the good corrosion resistance of Zn-Ni alloy, it is selected in the present study to be the protective coating on mild steel and it is considered as a strong candidate for the replacement of environmentally hazardous cadmium. Zn-Ni alloy coating is applied by electrodeposition at optimum temperature, current density and time. The bath solution used is consisting of EDTA as complexing agent. The electrodeposition is also carried out with tartaric acid and benzaldehyde additives to have good corrosion resistance and brightness. The electrodeposits obtained with and without additives are examined for nature and alloy composition. The corrosion behaviour of the electrodeposits is studied by Tafel polarization and electrochemical impedance spectroscopy.

2018 ◽  
Vol 9 (1) ◽  
pp. 9-16 ◽  
Author(s):  
Ramesh Bhat ◽  
Ampar Chitharanjan Hegde

Chloride bath containing ZnCl2 ∙7H2O, FeCl2 ∙H2O and a combination of sulphamic acid and citric acid (SA+CA) were optimized for electrodeposition of bright Zn-Fe alloy coating on the mild steel. Bath constituents and operating parameters were optimized by the Hull cell method for highest performance of the coating against corrosion. The effect of current density and temperature on deposit characteristics such as corrosion resistance, hardness, thickness, cathode current efficiency and glossiness, were studied. Potentiodynamic polarization and electrochemical impedance spectroscopic (EIS) methods were used to assess corrosion behaviour. Surface morphology of coatings was examined using scanning electron microscopy (SEM). The Zn-Fe alloy with intense peaks corresponding to Zn (100) and Zn (101) phases, evidenced by X-ray diffraction (XRD) study, showed the highest corrosion resistance. A new and economical chloride bath for electrodeposition of bright Zn-Fe alloy coating on mild steel was proposed and discussed.


2018 ◽  
Vol 18 ◽  
pp. 19-26
Author(s):  
Nadjette Belhamra ◽  
Abd Raouf Boulebtina ◽  
Khadidja Belassadi ◽  
Abdelouahed Chala ◽  
Malika Diafi

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.


Coatings ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 106
Author(s):  
Akbar Ali Samsath Begum ◽  
Raja Mohamed Abdul Vahith ◽  
Vijay Kotra ◽  
Mohammed Rafi Shaik ◽  
Abdelatty Abdelgawad ◽  
...  

In the present study, the corrosion inhibition effect of Spilanthes acmella aqueous leaves extract (SA-LE) on mild steel was investigated in 1.0 M HCl solution at different temperature using weight loss, Tafel polarization, linear polarization resistance (LPR), and electrochemical impedance (EIS) measurements. Adsorption of inhibitor on the surface of the mild steel obeyed both Langmuir and Temkin adsorption isotherms. The thermodynamic and kinetic parameters were also calculated to determine the mechanism of corrosion inhibition. The inhibition efficiency was found to increase with an increase in the inhibitor concentration i.e., Spilanthes acmella aqueous leaves extract, however, the inhibition efficiency decreased with an increase in the temperature. The phytochemical constituents with functional groups including electronegative hetero atoms such as N, O, and S in the extract adsorbed on the metal surface are found responsible for the effective performance of the inhibitor, which was confirmed by Fourier-transform infrared spectroscopy (FT-IR) and ultraviolet–visible spectroscopic (UV-Vis) studies. Protective film formation against corrosion was confirmed by scanning electron microscopy (SEM), atomic force microscopy (AFM), and contact angle studies. The result shows that the leaves extract acts as corrosion inhibitor and is able to promote surface protection by blocking active sites on the metal.


2005 ◽  
Vol 11 (S03) ◽  
pp. 82-85 ◽  
Author(s):  
E. T. Uzumaki ◽  
C. S. Lambert ◽  
A. R. Santos Jr. ◽  
C. A. C. Zavaglia

Diamond-like carbon (DLC) films have been intensively studied with a view to improving orthopaedic implants. Studies have indicated smoothness of the surface, low friction, high wear resistance, corrosion resistance and biocompatibility [1-4]. DLC coatings can be deposited using various techniques, such as plasma assisted chemical vapour deposition (PACVD), magnetron sputtering, laser ablation, and others [5]. However it has proved difficult to obtain films which exhibit good adhesion. The plasma immersion process, unlike the conventional techniques, allows the deposition of DLC on three-dimensional workpieces, even without moving the sample, without an intermediate layer, and with high adhesion [6], an important aspect for orthopaedic articulations. In our previous work, DLC coatings were deposited on silicon and Ti-13Nb-13Zr alloy substrates using the plasma immersion process for the characterization of microstructure, mechanical properties and corrosion behaviour [7-9]. Hardness, measured by a nanoindenter, ranged from 16.4-17.6 GPa, the pull test results indicate the good adhesion of DLC coatings to Ti-13Nb-13Zr, and electrochemical assays (polarization test and electrochemical impedance spectroscopy) indicate that DLC coatings produced by plasma immersion can improve the corrosion resistance [9].


2016 ◽  
Vol 8 (3) ◽  
pp. 1716-1735
Author(s):  
C. Kumar ◽  
A. John Amal Raj ◽  
S.K. Selvaraj

Human tear comes in contact with a number of instruments during operation in the eyes.  This results in a variety of undesirable effects such as corrosion and malfunction.  Corrosion behaviour of five metals, namely, mild steel (MS), mild steel coated with zinc (MS-Zn), Ni-Cr, Ni-Ti super elastic (Ni-Ti.SE), and SS 316 L in artificial tear solution has been studied by polarization study and AC impedance spectra.  The study reveals that the decreasing order of corrosion resistance in artificial tear solution is : Ni-Ti SE > Ni-Cr > SS 316 L > MS-Zn > MS.  The first three metals are better candidates and the first one is the best candidate for making instruments used in operation in the eyes, in presence of tears.


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.


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.


2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Kashmitha Muthamma ◽  
Preethi Kumari ◽  
M. Lavanya ◽  
Suma A. Rao

Abstract Mild steel (a low carbon steel) is an affordable engineering material used for many purposes in various environments including mild acidic environment with some precautions. The corrosion behaviour of mild steel (MS) in 0.5 M H2SO4 and 0.5 M HCl, in the temperature range (303–323 K) without and with the inhibitor N-[(3,4-dimethoxyphenyl) methyleneamino]-4-hydroxy-benzamide (DMHB), was investigated using Potentiodynamic polarization and Electrochemical impedance spectroscopy (EIS) techniques supplementing with surface characterization study using scanning electron microscope (SEM) and atomic force spectroscopy (AFM). Experimental observations were found to be in agreement with Density functional theory (DFT) calculations. The inhibition efficiency increases with increase in DMHB concentration and showed maximum inhibition efficiency of 86% in 0.5 M H2SO4 and 81% in 0.5 M HCl, respectively, at concentration of 3 × 10─3 M at 303 K. The inhibition efficiency of DMHB obtained relatively at its lower concentration (3 × 10─3 M) compared to other reported related compounds confirms its potential towards corrosion inhibition. The variation in the kinetic and thermodynamic parameters indicated physisorption of DMHB on MS and its mixed type inhibitive action followed Langmuir’s isotherm model. DFT calculations go along with the experimental results, signifying the potential corrosion inhibition behaviour of DMHB for MS in both the acid media.


2011 ◽  
Vol 291-294 ◽  
pp. 65-71 ◽  
Author(s):  
Qing Jun Chen ◽  
Lin Li Hu ◽  
Xian Liang Zhou ◽  
Xiao Zhen Hua ◽  
Ying Jun Yang

The purpose of this study is to investigate the electrochemical properties of Fe44Cr16Mo16C18B6amorphous alloy coating fabricated using high velocity oxygen fuel (HVOF) technology in 2.0M HCl and NaOH solution at room temperature(25°C). Based on the potentiodynamic polarization curves and Electrochemical Impedance Spectroscopy(EIS) testing results of coating in aqueous solutions of HCl and NaOH, the corrosion resistance of Fe44Cr16Mo16C18B6amorphous alloy coating in HCl solution was superior to that in NaOH solution. The icorrwas 1.487×10-5A·cm-2in HClsolution and 1.107×10-4A·cm-2in NaOH solution, while the Rtreach to 5.789×104Ω·cm2and 9780Ω·cm2, respectively. On the other hand, these corrosion phenomenon could be better interpreted by R(Q(R(RQW)))(RL) and R(RL)(Q(R(CW))) equivalent circuit model, which were different from that of other Fe-based amorphous alloys in HCl and NaOH solution, respectively.


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