scholarly journals Low-Voltage Polarization in AOT Solution to Enhance the Corrosion Resistance of Nitinol

2021 ◽  
Author(s):  
Melisa Saugo ◽  
Daniel O. Flamini ◽  
Silvana B. Saidman
Keyword(s):  
Corrosion Inhibitor ◽  
Oxide Layer ◽  
Pitting Corrosion ◽  
Low Voltage ◽  
Niti Alloy ◽  
Research Work ◽  
Open Circuit ◽  
Ringer’S Solution ◽  
Passive Behavior ◽  
Surface Analysis Techniques

AbstractIn this work, the corrosion behavior of bare nitinol (NiTi) alloy in Ringer's solution containing different concentrations of sodium bis(2-ethylhexyl) sulfosuccinate (AOT) was first studied in order to determine whether the surfactant acts as a corrosion inhibitor. Results of potentiostatic and potentiodynamic experiments allowed concluding that AOT is a pitting corrosion inhibitor for NiTi. In a second stage of this research work, NiTi was treated under potentiostatic control (2.00 V) for 1 h in 0.10 M AOT solutions of pH 8.4 and 12. Static and rotating electrodes were used. The influence exerted by this treatment on the passive behavior of the alloy was studied in Ringer's solution using different electrochemical and surface analysis techniques. The best anticorrosion performance was obtained using a rotating electrode and AOT solution of pH 8.4. The thin oxide layer grown potentiostatically consists of TiO2, while no Ni was found in the outermost layer. The presence of this oxide layer allows reducing the amount of Ni and Ti released at open circuit potential conditions and at very positive potentials where pitting corrosion of the bare alloy occurs.

Application of EIS to Study the Corrosion Resistance of Passivated NiTi Shape Memory Alloy in Simulated Body Fluid

2011 ◽  
Vol 183 ◽  
pp. 57-64 ◽  
Author(s):  
Marlena Freitag ◽  
B. Łosiewicz ◽  
Tomasz Goryczka ◽  
Józef Lelątko
Keyword(s):  
Corrosion Resistance ◽  
Shape Memory Alloy ◽  
Simulated Body Fluid ◽  
Shape Memory ◽  
Pitting Corrosion ◽  
Body Fluid ◽  
Niti Alloy ◽  
Amorphous State ◽  
Open Circuit ◽  
Niti Shape Memory Alloy

The NiTi shape memory alloy passivated for 90 min by autoclaving has been studied towards corrosion performance in the Tyrode’s simulated body fluid using open circuit potential and EIS measurements. The surface morphology and thickness of the oxide layer was determined by XRR. The HREM was used to observe the cross-section of the thin foil and to confirm the amorphous state of the TiO2 layer and its thickness. Electrochemical measurements revealed a good corrosion resistance at the beginning of long-term (20 days) immersion. It was found that with the increase of immersion time, the corrosion resistance of the surface deteriorated after nearly 1 day of immersion due to occurence of pitting corrosion. The EIS method was used to detailed study on the electrolyte | passive layer interfacial properties. Equivalent electrical circuit for the pitting corrosion on the passivated NiTi alloy has been applied.

scholarly journals Influence of pH and Fluoride Species on the Corrosion Behavior of Ti-xNb-13Zr Alloys in Ringer’s Solution

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
A. Robin ◽  
O. A. S. Carvalho
Keyword(s):  
Corrosion Resistance ◽  
Electrochemical Impedance ◽  
Corrosion Behaviour ◽  
Open Circuit ◽  
Ringer’S Solution ◽  
Passive Behavior ◽  
Low Elastic Modulus ◽  
Cp Ti ◽  
Influence Of Ph ◽  
Zr Alloys

Ti-Nb-Zr alloys are interesting materials for implant applications due to the atoxic character of the Nb and Zr alloying elements and to their low elastic modulus when compared to CP-Ti. In this work, the corrosion behaviour of CP-Ti, Ti-5Nb-13Zr, Ti-13Nb-13Zr, and Ti-20Nb-13Zr alloys was investigated in Ringer’s solution of pH 2, 5, and 7.5 without fluorides and containing 1000 ppm F at 37°C, through open-circuit potential measurements, potentiodynamic polarization, and electrochemical impedance spectroscopy. The four materials showed a passive behavior in Ringer's solution without fluorides for pH ranging from 2 to 7.5 and in Ringer's solution of pH 5 and 7.5 containing 1000 ppm F but presented an active behavior in Ringer's solution of pH 2 containing fluorides. The corrosion resistance of all materials in Ringer's solution decreases with both decrease of pH and addition of fluorides. Ti-13Nb-13Zr alloy is a little more corrosion resistant than the Ti-5Nb-13Zr and Ti-20Nb-13Zr alloys and, in most conditions, the Ti-Nb-Zr alloys present higher corrosion resistance than CP-Ti.

scholarly journals Dielectric screening in perovskite photovoltaics

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Rui Su ◽  
Zhaojian Xu ◽  
Jiang Wu ◽  
Deying Luo ◽  
Qin Hu ◽  
...  
Keyword(s):  
Open Circuit Voltage ◽  
Low Voltage ◽  
Power Conversion ◽  
Surface Recombination ◽  
Open Circuit ◽  
Phonon Coupling ◽  
Electron Phonon Coupling ◽  
Dielectric Screening ◽  
Perovskite Photovoltaic ◽  
Reduced Surface

AbstractThe performance of perovskite photovoltaics is fundamentally impeded by the presence of undesirable defects that contribute to non-radiative losses within the devices. Although mitigating these losses has been extensively reported by numerous passivation strategies, a detailed understanding of loss origins within the devices remains elusive. Here, we demonstrate that the defect capturing probability estimated by the capture cross-section is decreased by varying the dielectric response, producing the dielectric screening effect in the perovskite. The resulting perovskites also show reduced surface recombination and a weaker electron-phonon coupling. All of these boost the power conversion efficiency to 22.3% for an inverted perovskite photovoltaic device with a high open-circuit voltage of 1.25 V and a low voltage deficit of 0.37 V (a bandgap ~1.62 eV). Our results provide not only an in-depth understanding of the carrier capture processes in perovskites, but also a promising pathway for realizing highly efficient devices via dielectric regulation.

Pulsed anodization of NiTi alloy to form a biofunctional Ni-free oxide layer for corrosion protection and hydrophilicity

2021 ◽  
Vol 412 ◽  
pp. 127039 ◽  
Author(s):  
Naofumi Ohtsu ◽  
Kako Yamasaki ◽  
Hiroki Taniho ◽  
Yusuke Konaka ◽  
Kasumi Tate
Keyword(s):  
Oxide Layer ◽  
Corrosion Protection ◽  
Niti Alloy

Experimental Study of Propagation Stage of Pitting Corrosion of 20Cr13 Steel

2008 ◽  
Vol 38 ◽  
pp. 238-247
Author(s):  
A.D. Davydov ◽  
V.S. Shaldaev
Keyword(s):  
Pitting Corrosion ◽  
Open Circuit Potential ◽  
Corrosion Potential ◽  
Ph Value ◽  
Open Circuit ◽  
Effect Of Temperature ◽  
Pitting Potential ◽  
Free Corrosion Potential ◽  
External Power Source ◽  
Corrosion Of Steel

The initiation and development of pitting corrosion of steel 20Cr13 in the NaCl solutions with various concentrations, temperatures, and pH values are studied under the potentiostatic conditions and at the free-corrosion potential. The pitting and repassivation potentials are determined using the method of cycling voltammetry. In spite of the fact that thus determined pitting potential is more positive than the corrosion potential (the open-circuit potential Eo.c.), the long-term experiments, which were performed at the free-corrosion potential, showed that pitting corrosion takes place without imposing a potential using an external power source. It is concluded that the probability of pitting corrosion of steel should be determined by comparing the corrosion potential (the open-circuit potential) with the repassivation potential Erp. Steel 20Cr13 is prone to the pitting corrosion, because Erp is more negative than Eo.c.. In the potentiostatic experiments, the variation of the depth and diameter of pits and their number with the time and the effect of temperature and electrode rotation on the pit propagation are studied. The results, which were obtained at the free-corrosion potential, are much less reproducible. In this case, in contrast to the potentiostatic conditions, the pit depth increased only slightly and the pit width increased to a larger extent. The effect of concentration, pH value, and temperature of NaCl solutions on the pit propagation is considered. It is concluded that the data on the development of pitting corrosion under the potentiostatic conditions can be hardly extended to the conditions of free corrosion potential.

Structure and Resistance to Electrochemical Corrosion of NiTi Alloy

2013 ◽  
Vol 203-204 ◽  
pp. 335-338 ◽  
Author(s):  
Bożena Łosiewicz ◽  
Magdalena Popczyk ◽  
Tomasz Goryczka ◽  
Józef Lelątko ◽  
Agnieszka Smołka ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Niti Alloy ◽  
Electrochemical Corrosion ◽  
High Resolution Electron Microscopy ◽  
Potential Method ◽  
Passive Layer ◽  
Open Circuit ◽  
Experimental Conditions ◽  
Electrochemical Tests ◽  
Reflectivity Method

The NiTi alloy (50.6 at.% Ni) passivated for 30 min at 130°C by autoclaving has been studied towards corrosion resistance in aqueous solutions of 3% NaCl, 0.1 M H2SO4, 1 M H2SO4 and HBSS. Structure and thickness of the passive layer (TiO2, rutile) were examined by X-ray reflectivity method and high resolution electron microscopy. Corrosion behavior of this oxide layer was investigated by open circuit potential method and polarization curves. It was found that the corrosion resistance of the passivated NiTi alloy is strongly dependent on the type of corrosive environment. The higher corrosion resistance of the tested samples was revealed in sulfate solutions as compared to chloride ones. The highest resistance to electrochemical corrosion of the NiTi alloy was observed in 0.1 M H2SO4 solution. Susceptibility to pitting corrosion of the tested samples was observed which increased with the concentration rise of chlorine anions in solution. Electrochemical tests for 316L stainless steel carried out under the same experimental conditions revealed a weaker corrosion resistance in all solutions as compared to the highly corrosion resistant NiTi alloy.

Nano-Thick Amorphous Oxide Layer Produced by Plasma on Type 316L Stainless Steel for Improved Corrosion Resistance Under Plastic Deformation

CORROSION ◽  
10.5006/2674 ◽  
2018 ◽  
Vol 74 (9) ◽  
pp. 1011-1022 ◽  
Author(s):  
Megan Mahrokh Dorri ◽  
Stéphane Turgeon ◽  
Maxime Cloutier ◽  
Pascale Chevallier ◽  
Diego Mantovani
Keyword(s):  
Plastic Deformation ◽  
Stainless Steel ◽  
Oxide Layer ◽  
Electrochemical Impedance ◽  
Open Circuit ◽  
Localized Corrosion ◽  
Native Oxide ◽  
Native Oxide Layer ◽  
Amorphous Oxide ◽  
Amorphous Oxide Layer

Localized corrosion constitutes a major concern in medical devices made of stainless steel. The conventional approach to circumvent such a problem is to convert the surface polycrystalline microstructure of the native oxide layer to an amorphous oxide layer, a few micrometers thick. This process cannot, however, be used for devices such as stents that undergo plastic deformation during their implantation, especially those used in vascular surgery for the treatment of cardiac, neurological, and peripheral vessels. This work explores the feasibility of producing a nano-thick plastic-deformation resistant amorphous oxide layer by plasma-based surface modifications. By varying the plasma process parameters, oxide layers with different features were produced and their properties were investigated before and after clinically-relevant plastic deformation. These properties and the related corrosion mechanisms were mainly evaluated using the electrochemical methods of open-circuit potential, cyclic potentiodynamic polarization, and electrochemical impedance spectroscopy. Results showed that, under optimal conditions, the resistance to corrosion and to the permeation of ions in a phosphate buffered saline, even after deformation, was significantly enhanced.

scholarly journals MLR institute of technology campus energy monitoring and controlling system with interconnection of grid and solar power

2020 ◽  
Vol 9 (2) ◽  
pp. 424
Author(s):  
M. Sreenivasa reddy ◽  
A. Shubhangi Rao ◽  
Ch. Sai Prakash
Keyword(s):  
Power Factor ◽  
Solar Power ◽  
Low Voltage ◽  
Short Circuit ◽  
Open Circuit ◽  
Power Generating Unit ◽  
Power Resources ◽  
Controlling System ◽  
Institute Of Technology ◽  
Campus Energy

This paper mainly deals with energy consumption and monitoring of each block after carefully observing where the losses occur and how to minimize these losses and how to reduce unit consumption of each block and units consumed by capacitor bank. Base loads and Peak loads can be observed and operated in such a way as to reduce unit consumption.MLR college has 315KVA power from the grid as well as 260KW solar power generating unit where 40 percent of the power from the grid is saved. Proper planning for operating the underground bore motors used for Hostels, Mess and College buildings also saves some amount of units consumed by these motors. Further if power factor is maintained 0.99 instead of 0.2 or 0.3 some amount of units consumed can be saved. Further if maximum demand is prevented from reaching beyond the transformer rating then some amount of units consumed can be saved. Installing copper earth pits of suitable numbers for each block and balancing the loads in each phase can also reduce the losses.Synchronizing panel is to be connected to the existing 4 generators of rating 200KVA,180KVA and two numbers of 125 KVA to utilize the power resources properly.The common electrical problems like short circuit, open circuit, over voltage, low voltage, frequent power cuts, low power factor, high electricity bills damage in the meters etc. The above electrical problems are identified, rectified and frequently monitored through modern technologies like IOT.  

scholarly journals A NEW AND SUSTAINABLE PKL ELECTRICITY

2021 ◽  
Author(s):  
K. A. Khan ◽  
Shahinul Islam ◽  
M. A. Saime ◽  
S. R. Rasel ◽  
Sazzad Hossain
Keyword(s):  
Rural Areas ◽  
Electricity Generation ◽  
Short Circuit ◽  
Storage System ◽  
Research Work ◽  
Titratable Acidity ◽  
Voltage Regulation ◽  
Open Circuit ◽  
Electricity Production ◽  
Maximum Efficiency

A new method of electricity generation based on Pathor Kuchi Leaf (Genus: Kalanchoe, Section: Bryophyllum) has been developed at the Department of Physics, Jagannath University, Dhaka- 1100, Bangladesh. This electricity generation method has several advantages for smart grid over the conventional electricity production. This sustainable method is likely to generate the employment at particularly in the rural areas of where grid electricity is absent. This research work reports an invention made on Pathor Kuchi Leaf (PKL) electric power plant to enhance the PKL electricity production. The efficiency of the PKl electricity production device, Short Circuit Current ( Isc ), Open circuit Voltage ( Voc ), Temperature effect of the PKL malt, pH of the PKL malt, Titratable acidity of the PKL malt, Generation of PKL electricity, Storage system of the PKL electricity, Particular utilization of PKL electricity, I-V characteristics of the PKL, Classification of PKL, Longevity of PKL malt for PKL electricity generation, Preparation of PKL electric unit cell, module, panel, arrays and the constituent elements of the PKL, Voltage regulation, Internal resistance of the cell and efficiency of the cell have been studied. The chemical reactions of the PKL electrochemical cell have also been studied. In experimental study, it is shown that the maximum efficiency of the PKL electricity production device is ≈ 34%, the pH of the PKL malt is ≈ 4.6(without water), pH of the PKL malt is ≈ 4.8 (with 10% solution), the titratable acidity of the PKL malt is ≈ 0.88%. Most of the results have been tabulated and graphically discussed.

N-cetyl-N,N,N trimethyl ammonium bromide (CTAB)-stabilized polyaniline: a corrosion inhibitor for mild steel

2018 ◽  
Vol 65 (2) ◽  
pp. 146-151 ◽  
Author(s):  
Mohd Rashid ◽  
Umesh S. Waware ◽  
Afidah A. Rahim ◽  
A.M.S. Hamouda
Keyword(s):  
Mild Steel ◽  
Corrosion Inhibitor ◽  
Corrosion Inhibition ◽  
Potentiodynamic Polarization ◽  
Acidic Medium ◽  
Electrochemical Impedance ◽  
Open Circuit ◽  
High Dispersion ◽  
Ammonium Bromide ◽  
Content Type

Purpose The purpose of this study is to compare the inhibitive effect of polyaniline (PAni) and N-cetyl-N,N,N trimethyl ammonium bromide (CTAB)-stabilized PAni in a hydrochloric acid (HCl) medium. Design/methodology/approach PAni has been deposited potentiodynamically on mild steel in the presence of CTAB as a stabilizing agent to achieve high corrosion inhibition performance by the polymer deposition. The corrosion inhibition studies of CTAB-stabilized PAni inhibitor in 0.1 M HCl acidic solution was carried out by electrochemical methods, namely, open-circuit potential, potentiodynamic polarization and electrochemical impedance spectroscopy technique. Findings The results of electrochemical studies have shown that the CTAB-stabilized PAni inhibitor has higher corrosion efficiency than PAni on mild steel in 0.1 M HCl solution. The maximum per cent efficiency evaluated using the potentiodynamic polarization method is approximately 91.9. Originality/value CTAB-stabilized PAni has never been studied as a corrosion inhibitor for mild steel in an acidic medium. The investigations demonstrate relatively the better corrosion inhibition efficiency and high dispersion of the polymer in the acidic medium.

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