scholarly journals Corrosion Behaviour of Metals in Artificial Tear Solution

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.

2021 ◽  
Vol 62 (3) ◽  
pp. 191-203
Author(s):  
Josephath Praveena ◽  
Somasundaram Gowri ◽  
Gunasekaran Nethravathi ◽  
Vincent Varsha ◽  
Arockiasamy Vieyana ◽  
...  

The corrosion resistance of SS 18/8 in natural sea water, in presence of an inhibitor named Thiourea-Zn2+ has been evaluated. Weight loss method, polarization study and AC impedance spectra have been employed to evaluate the corrosion resistance of SS 18/8 alloy in natural sea water, in presence of an inhibitor named Thiourea-Zn2+ system. Weight loss method reveals that Thiourea-Zn2+ system offers a maximum corrosion inhibition efficiency of 95% in controlling corrosion of SS 18/8 alloy in natural sea water. Synergism parameters are found to be greater than 1, confirming the synergistic effect existing between Thiourea-Zn2+. Adsorption of inhibitor molecules on the metal surface obey Langmuir adsorption isotherm. Polarisation study reveals that the inhibitors named Thiourea-Zn2+ system functions as mixed type of inhibitor. AC impedance spectra confirm the formation of a protective film on the metal surface. This formulation of Thiourea-Zn2+ may be used in cooling water systems where SS 18/8 alloy pipelines are used to carry sea water which is used as coolant. Also, Thiourea-Zn2+ coating can be given on SS 18/8 alloy to protect it from corrosion by sea water when SS 18/8 alloy is used as hull plates in ship industry.


2021 ◽  
Vol 62 (4) ◽  
pp. 277-290
Author(s):  
Josephath Praveena ◽  
Jeyaraj Clara ◽  
Susai Rajendran ◽  
Antony Amalraj

Inhibition efficiency of an aqueous extract of soapnut (Sapindus Trifoliatus) and Zn2+in controlling corrosion of mild steel in well water at room temperature has been evaluated by using weight loss method, polarization study and AC impedance spectra. Dynamic light scattering and Vickers hardness have also been employed. Weight loss method reveals that the formulation consisting of 10 ml soapnut extract and 50 ppm Zn2+ has 97 % inhibition efficiency in controlling corrosion of mild steel immersed in well water. Synergism parameters suggest that a synergistic effect exists between soapnut extract and Zn2+. Adsorption isotherm of metal surface obeys Langmuir adsorption isotherm. Polarization study reveals that the inhibitor system functions as anodic type of inhibitor. AC impedance spectra confirm the protective film formed on the metal surface. Dynamic light scattering (DLS) study reveals surface is in nano meter scale. The Vickers hardness of metal surface was increases in inhibitor system.


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.


2004 ◽  
Vol 151 (5) ◽  
pp. E186 ◽  
Author(s):  
Alan Atkinson ◽  
Sylvia A. Baron ◽  
Nigel P. Brandon

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.


Coatings ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1318
Author(s):  
Abdulaziz S. Alghamdi ◽  
K. S. Abdel Halim ◽  
Mohammed A. Amin ◽  
Abdullah S. Alshammari ◽  
Naglaa Fathy ◽  
...  

The improvement of the surface properties of ferrous metallic materials has become a crucial criterion for advanced engineering applications. The interfacial microstructure and corrosion behaviour of mild steel coated with alumina nanoparticles doped in tin composite using the direct tinning technique were investigated. A coating layer of tin composite containing different loads of Al2O3 nanoparticles (0.25 wt.%, 0.50 wt.%, 1.00 wt.% and 1.5 wt.%) was prepared and directly deposited on a mild steel substrate. This type of a direct tinning process is considered to be a simple and low-cost route for protecting metallic materials from corrosion. It was found that the thickness of both the composite layer and Fe-Sn intermetallic layer at the coated interfaces was highly affected by the presence of alumina nanoparticles that effectively inhibit the diffusion of Sn atoms into the Fe substrate. For the samples coated with lower content of alumina nanoparticles (0.25 wt.% and 0.50 wt.%), the thickness of the Fe-Sn intermetallic coating (IMC) layer is decreased due to Fe-Sn IMC suppression. Otherwise, for the addition of more alumina nanoparticles (1.00 wt.% and 1.50 wt.%), the thickness of the Fe-Sn IMC layer is slightly increased because of nanoparticle’s agglomeration and flotation. It can be reported that the presence of alumina nanoparticles in the coating layer improves, to a great extent, the corrosion resistance of Sn-composites surface on mild steel substrates. Although the tin composite coating layer with a high quantity of alumina nanoparticles (1.0 wt.%) exhibited better corrosion resistance than the other tested samples, such nanoparticle additions have become increasingly difficult to obtain. It was observed that the Al2O3 nanoparticles agglomeration and flotation that were detected in the coating surface may be related to high fraction nanoparticles loading and to the difference in the gravity for Sn and Al2O3 nanoparticles. However, based on our investigation, a coating layer that contains 0.50 wt.% alumina nanoparticles is highly recommended for achieving long lasting and high-performance corrosion resistance for coated mild steel with minimal coating layer defects.


2011 ◽  
Vol 10 (01n02) ◽  
pp. 81-85 ◽  
Author(s):  
PARAMESWAR HARI ◽  
MICHAL BYRCZEK ◽  
DALE TEETERS ◽  
PRAVIN UTEKAR

ZnO nanorods grown by hydrothermal technique on glass, Zinc, and Indium tin oxide (ITO) substrates exhibit both open and closed hexagonal structures. On the nanoscale, closed ZnO nanostructures exhibit two types of ion conduction regions as revealed by AC-impedance spectra collected through the tip of an atomic force microscope (AFM). One region has higher impedance values (apparent values of approximately 107 ohms) with two semicircles. Two semicircles are indicative of a ZnO structure composed of bulk and grain boundary conduction. Other regions were found to have impedance values that were two orders of magnitude lower (apparent values of 105 ohms). This indicates that these ZnO films have two conduction pathways. The polyethylene oxide ( PEO )– ZnO nanorod composite was made by spin-coating the ZnO rods growing from the ITO substrate with PEO. In the PEO – ZnO composite film, only the AC impedance values of 105 ohms were observed. This is higher than PEO electrolyte without ZnO nanorods. Since regions of higher impedance were not seen in the PEO – ZnO nanorod composites, the polymer electrolyte either dominated the conduction of the system or suppressed the first pathway of higher impedance in the ZnO rods.


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