scholarly journals Nano-TiO2 Phosphate Conversion Coatings – A Chemical Approach

2018 ◽  
Vol 4 (1) ◽  
pp. 47-54 ◽  
Author(s):  
Nilesh S. Bagal ◽  
Vaibhav S. Kathavate ◽  
Pravin P. Deshpande
Keyword(s):  
Corrosion Resistance ◽  
Electrochemical Impedance Spectroscopy ◽  
Carbon Steel ◽  
Impedance Spectroscopy ◽  
Zinc Phosphate ◽  
Electrochemical Impedance ◽  
Low Carbon Steel ◽  
Low Carbon ◽  
Phosphate Coatings ◽  
Coating Weight

AbstractThe present study aims at deposition of zinc phosphate coatings on low carbon steel with incorporated nano- TiO2 particles by chemical phosphating method. The coated low carbon steel samples were assessed in corrosion studies using electrochemical impedance spectroscopy and potentiodynamic polarization techniques (Tafel) in 3.5% NaCl solution. Morphology and chemical composition of the coatings were analyzed by scanning electron microscopy and energy dispersive X-ray spectroscopy in order to observe growth of coating. Significant variations in the coating weight, porosity and corrosion resistance were observed with the addition of nano- TiO2 in the phosphating bath. Corrosion rate of nano-TiO2 chemical phosphate coated samples was found to be 3.5 milli inches per year which was 3 times less than the normal phosphate-coated sample (8 mpy). Electrochemical impedance spectroscopy studies reveal reduction of porosity of nano-TiO2 phosphate coated samples. It was found that nano-TiO2 particles in the phosphating solution yielded uniform phosphate coatings of higher coating weight, fewer defects and enhanced corrosion resistance than the normal zinc phosphate coatings (developed using normal phosphating bath).

scholarly journals Nano Metal Dioxide Incorporated Conversion Phosphate Coatings—A Chemical Approach

2016 ◽  
Author(s):  
Nilesh S. Bagal ◽  
Vaibhav S. Kathavate ◽  
Pravin P. Deshpande
Keyword(s):  
Corrosion Resistance ◽  
Electrochemical Impedance Spectroscopy ◽  
Carbon Steel ◽  
Zinc Phosphate ◽  
Electrochemical Impedance ◽  
Low Carbon Steel ◽  
Low Carbon ◽  
Nano Tio2 ◽  
Phosphate Coatings ◽  
Coating Weight

The present study aims at deposition of zinc phosphate coatings with the incorporation of nano Titanium dioxide particles by chemical phosphating method. Zinc phosphate coatings were developed on low carbon steel by using nano TiO2 in the standard phosphating bath. The Coated low carbon steel samples were assessed for corrosion studies using electrochemical impedance spectroscopy and potentiodynamic polarisation techniques in 3.5% NaCl solution. Chemical composition of the coatings was analysed by energy dispersive X-ray spectroscopy (EDX). Significant variations in the coating weight, porosity and corrosion resistance were observed with the addition of nano TiO2 in the phosphating bath. Corrosion rate of nano TiO2 incorporated chemical phosphate coated samples was found to be 3.5 mpy which was 4 times less than the bare uncoated low carbon steel (~14 mpy). Electrochemical impedance spectroscopy studies revels in the reduction of porosity in nano TiO2 phosphate coated samples. It was found that nano TiO2 particles in the phosphating solution yielded phosphate coatings of higher coating weight, greater surface coverage and enhanced corrosion resistance than the normal zinc phosphate coatings (developed using normal phosphating bath).

scholarly journals Nano Metal Dioxide Incorporated Conversion Phosphate Coatings—A Chemical Approach

2016 ◽  
Author(s):  
Nilesh S. Bagal ◽  
Vaibhav S. Kathavate ◽  
Pravin P. Deshpande
Keyword(s):  
Corrosion Resistance ◽  
Electrochemical Impedance Spectroscopy ◽  
Carbon Steel ◽  
Zinc Phosphate ◽  
Electrochemical Impedance ◽  
Low Carbon Steel ◽  
Low Carbon ◽  
Nano Tio2 ◽  
Phosphate Coatings ◽  
Coating Weight

The present study aims at deposition of zinc phosphate coatings with the incorporation of nano Titanium dioxide particles by chemical phosphating method. Zinc phosphate coatings were developed on low carbon steel by using nano TiO2 in the standard phosphating bath. The Coated low carbon steel samples were assessed for corrosion studies using electrochemical impedance spectroscopy and potentiodynamic polarisation techniques in 3.5% NaCl solution. Chemical composition of the coatings was analysed by energy dispersive X-ray spectroscopy (EDX). Significant variations in the coating weight, porosity and corrosion resistance were observed with the addition of nano TiO2 in the phosphating bath. Corrosion rate of nano TiO2 incorporated chemical phosphate coated samples was found to be 3.5 mpy which was 4 times less than the bare uncoated low carbon steel (~14 mpy). Electrochemical impedance spectroscopy studies revels in the reduction of porosity in nano TiO2 phosphate coated samples. It was found that nano TiO2 particles in the phosphating solution yielded phosphate coatings of higher coating weight, greater surface coverage and enhanced corrosion resistance than the normal zinc phosphate coatings (developed using normal phosphating bath).

Corrosion protection performance of nano-TiO2-containing phosphate coatings obtained by anodic electrochemical treatment

2019 ◽  
Vol 37 (6) ◽  
pp. 565-578 ◽  
Author(s):  
Vaibhav S. Kathavate ◽  
Nilesh S. Bagal ◽  
Pravin P. Deshpande
Keyword(s):  
Carbon Steel ◽  
Corrosion Protection ◽  
Zinc Phosphate ◽  
Electrochemical Impedance ◽  
Low Carbon Steel ◽  
Electrochemical Treatment ◽  
Phosphate Coating ◽  
Low Carbon ◽  
X Ray ◽  
Phosphate Coatings

AbstractThe efficacy of nano-TiO2-containing zinc phosphate coatings on low-carbon steel is investigated. Zinc phosphate coatings are electrodeposited on low-carbon steel (AISI 1015) keeping current density, deposition time and wt % nano-TiO2 at their respective levels. Corrosion protection performance of these coatings was assessed using potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS) in 3.5% NaCl electrolyte. The morphology, the composition and the growth process of the zinc phosphate coating is investigated using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy, X-ray diffraction (XRD) and electrochemical measurements. The XRD study reveals that the obtained phosphate layer contains traces of hopeite and phosphophylite. The formed zinc phosphate coating offers high corrosion protection in 3.5% NaCl solution, which is well supported by EIS studies. The presence of nano-TiO2 in the phosphate bath anticipated to offer a better surface coverage and reduction in porosity and forms more homogeneous coating, which is in agreement with the SEM studies. The optimization of the electrodeposition phosphating process for achieving better responses in terms of corrosion rate and coating resistance is addressed in this paper.

Effect of Nanoparticle Addition in Hybrid Sol-Gel Silane Coating on Corrosion Resistance of Low Carbon Steel

2013 ◽  
Vol 686 ◽  
pp. 244-249 ◽  
Author(s):  
Poovarasi Balan ◽  
Aaron Ng ◽  
Chee Beng Siang ◽  
R.K. Singh Raman ◽  
Eng Seng Chan
Keyword(s):  
Corrosion Resistance ◽  
Carbon Steel ◽  
Electrochemical Impedance ◽  
Sol Gel ◽  
Low Carbon Steel ◽  
Electrochemical Corrosion ◽  
Alumina Nanoparticles ◽  
Low Carbon ◽  
Silane Coating ◽  
Sol Gel Films

Chromium pre-treatments of metal have been replaced by silane pre-treatments as more environmental friendly option. Nanoparticles can be added in the silane sol-gel network have been reported to improve corrosion resistance. In this work, the electrochemical corrosion resistance of low carbon steel coated with hybrid organic-inorganic sol-gel film filled with nanoparticles was evaluated. The sol-gel films have been synthesized from 3-glycidoxy-propyl-trimethoxy-silane (3-GPTMS) and tetra-ethyl-ortho-silicate (TEOS) precursors. These films have been impregnated with 300 ppm of silica or alumina nanoparticles. The electrochemical behavior of the coated steel was evaluated by means of electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM). Equivalent circuit modeling, used for quantifying the EIS measurements showed that sol-gel films containing silica nanoparticles improved the barrier properties of the silane coating. The silica nanoparticle-containing films showed highest initial pore resistance over the five days of immersion in 0.05M NaCl.

Study of Corrosion Behavior of Friction Surfacing AA6351 Aluminium Alloy Coating on AISI 1020 Low Carbon Steel

2020 ◽  
Vol 1012 ◽  
pp. 401-406
Author(s):  
Carlos Trivellato de Carvalho Filho ◽  
Pedro Paiva Brito
Keyword(s):  
Surface Roughness ◽  
Corrosion Resistance ◽  
Carbon Steel ◽  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Low Carbon Steel ◽  
Alloy Coating ◽  
Low Carbon ◽  
Friction Surfacing ◽  
Finishing Process

In the present work, the friction surfacing process was applied to manufacture aluminum alloy (AA6351) coatings on low carbon steel (AISI 1020) substrates. After friction surfacing the AA6351 deposited coatings were submitted to two finishing process in order to adjust surface roughness: milling and milling followed by sanding. The corrosion behavior of the two finishing process was compared with the as-deposited condition in order to determine the influence of surface roughness on the corrosion resistance of friction surfacing coatings. The corrosion behavior was examined by electrochemical impedance spectroscopy and potentiodynamic polarization in a 3.5wt.%NaCl solution containing naturally dissolved O2. The results obtained indicated that the elevated surface roughness observed in the as-deposited condition led to relatively lower corrosion resistance in comparison, with lower values for polarization resistance and more anodic corrosion potential.

Corrosion Resistant Layers Produced in Vacuum Titanizing Process on a Low Carbon Steel Surface Coated Electrolytically with Cobalt

2014 ◽  
Vol 223 ◽  
pp. 110-118 ◽  
Author(s):  
Ewa Kasprzycka
Keyword(s):  
Corrosion Resistance ◽  
Carbon Steel ◽  
Electrochemical Impedance ◽  
Low Carbon Steel ◽  
Charge Transfer Resistance ◽  
Electrolytic Deposition ◽  
Low Carbon ◽  
Transfer Resistance ◽  
Diffusion Layers ◽  
Passive Current

Diffusion layers produced on low-carbon steel and iron surfaces by means of vacuum titanizing process have been studied. A new technological process combining a vacuum titanizing with a preliminary electrolytic deposition of cobalt has been proposed to increase the corrosion resistance of layers. As a result, diffusion duplex layers of a Ti+Co type on the low-carbon steel and iron surfaces have been obtained. The layers microstructure, their thickness, phase composition and concentration depth profiles of elements in the diffusion zone of these layers have been investigated. Microstructure studies of these layers were performed by metallographic microscopy, X-ray diffraction, and a SEM electron microscope with a BSE and an EDS spectrometer. In addition, the layers hardness and their corrosion resistance have been determined. Corrosion measurements were performed in 0.1 M H2SO4 by means of potentiodynamic polarization and electrochemical impedance tests. The highest corrosion resistance was observed for steel samples with the Ti+Co type duplex layers, which showed the least passive current density and the highest charge transfer resistance, whereas the titanized layers, and the steel without any layer, corroded actively.

scholarly journals Corrosion Behaviour of Cu/Carbon Steel Gradient Material

Crystals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1091
Author(s):  
Tao Ma ◽  
Huirong Li ◽  
Jianxin Gao ◽  
Yungang Li
Keyword(s):  
Corrosion Resistance ◽  
Electrochemical Impedance Spectroscopy ◽  
Carbon Steel ◽  
Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Copper Layer ◽  
Gradient Material ◽  
Cross Sectional ◽  
Steel Material ◽  
Corrosion Behaviors

Research on improving the corrosion resistance of carbon steel has become a hot topic in the iron and steel field in recent years. Copper plating on the surface of carbon steel is considered an effective means to improve its corrosion resistance, but the copper-plated carbon steel material prepared by this method has the problems of poor abrasion resistance, easy delamination of copper layer and similar issues, which affect the service performance of the copper-plated carbon steel material. To solve this problem, a new type of material whose surface is copper and the copper element is gradually diffused into carbon steel was developed by a plating-diffusion method, which is defined as a copper-carbon steel gradient material. Carbon steel with a copper plated surface and the Cu-Fe/carbon steel gradient material with 80% Cu content on the surface were prepared by the same method. The cross-sectional microstructure and composition of different samples were analysed, and the corrosion behaviors of samples in 3.5% NaCl solution were studied by the linear polarization curve method and electrochemical impedance spectroscopy. The cross-sectional microstructure result shows that the diffusion of copper in carbon is mainly carried out along its grain boundary, and the diffusion of copper will inhibit the growth of grains during heat treatment. As shown in the results of corrosion behaviors, there is no pitting corrosion in the corrosion process of all samples, as well as the stable passive film. All samples showed active dissolution. Compared with carbon steel, the corrosion potential of the Cu/carbon steel gradient material becomes more positive from −600 mV to −362 mV，the corrosion current density decreases from 53.0 μA/cm2 to 30.6 μA/cm2 and the radius of electrochemical impedance spectroscopy enlarges while the corrosion resistance is improved, and the corrosion resistance is mainly obtained by its surface copper layer. The corrosion resistance of Cu-Fe/carbon steel gradient material is lower than that of Cu/carbon steel gradient material, while it is still better than carbon steel, and it shows a clear passivation trend during corrosion. Therefore, the copper/carbon steel gradient material can significantly improve the corrosion resistance of carbon steel. Even after the surface copper layer is destroyed, the gradient material can protect the matrix and improve the service life of the material.

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