EFFECT OF HEAT TREATMENT OF SOLENOID CORE ON OPEN CIRCUIT PARAMETERS OF TWO MUTUALLY COUPLED COILS

Aluminium bronzes are exhibiting good corrosion resistance in saline environments combined with high mechanical properties. Their corrosion resistance is obviously confered by the alloy chemical composition, but it can also be improved by heat treatment structural changes. In the present paper, five Cu-Al-Fe-Mn bronze samples were subjected to annealing heat treatments with furnace cooling, water quenching and water quenching followed by tempering at three different temperatures: 200, 400 and 550�C. The heating temperature on annealing and quenching was 900�C. The structure of the heat treated samples was studied by optical and scanning electron microscopy. Subsequently, the five samples were submitted to corrosion tests. The best resistance to galvanic corrosion was showed by the quenched sample, but it can be said that all samples are characterized by close values of open-circuit potentials and corrosion potentials. Concerning the susceptibility to other types of corrosion (selective leaching, pitting, crevice corrosion), the best corrosion resistant structure consists of a solid solution, g2 and k compounds, corresponding to the quenched and 550�C tempered sample.

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Experimental study of the mechanical and corrosion properties of ethyl silicate resin applied on low carbon steel

Archives of Materials Science and Engineering ◽

10.5604/01.3001.0015.0255 ◽

2021 ◽

Vol 2 (108) ◽

pp. 68-74

Author(s):

M. Ali ◽

J.H. Mohmmed ◽

A.A. Zainulabdeen

Keyword(s):

Heat Treatment ◽

Carbon Steel ◽

Open Circuit Potential ◽

Low Carbon Steel ◽

Open Circuit ◽

Treatment Temperature ◽

Ethyl Silicate ◽

Low Carbon ◽

Corrosion Properties ◽

Mixture Ratio

Purpose: This work aimed at evaluating the properties of the ethyl silicate-based coating that can be applied on low carbon steel. Design/methodology/approach: Two mixture ratio types (2:1, and 3:2) of resin and hardener respectively were used to prepared two specimen models (A and B). Findings: It found that some mechanical properties (tensile, hardness, and impact strength) of ethyl silicate resin were evaluated according to standard criteria. Research limitations/implications: The effect of heat treatments at various temperatures (100, 150, and 200°C) and holding at different times (10, 20 & 30) min on hardness was investigated. Practical implications: Moreover, an open circuit potential corrosion test with a solution of 3.5% Sodium Chloride at room temperature and 60°C was used to determine the corrosion resistance of low carbon steel specimens coated with the two mixture types. Originality/value: The effects of mixture ratios (for resin and hardener) and heat treatment conditions on properties of ethyl silicate-based coating were studied. From obtained results, acceptable values of tensile, hardness, and toughness were recorded. Increasing heat treatment temperature and holding time leads to enhance hardness for both model types. An open circuit potential (OCP) tests show that there is an enhancement of protective properties of ethyl silicate coatings with mixture type B in comparison with type A was achieved. Generally, the results indicate that specimen model B has higher properties as compared with specimen model A.

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Defect Spectroscopy on Damp-Heat Treated ZnO/CdS/Cu(In,Ga)(S,Se)2/Mo Heterojunction Solar Cells

Zeitschrift für Naturforschung A ◽

10.1515/zna-2003-1205 ◽

2003 ◽

Vol 58 (12) ◽

pp. 691-702 ◽

Cited By ~ 4

Author(s):

C. Deibel ◽

V. Dyakonov ◽

J. Parisi

Keyword(s):

Heat Treatment ◽

Activation Energy ◽

Solar Cells ◽

Deep Level ◽

Heat Exposure ◽

Continuous Distribution ◽

Open Circuit ◽

Defect States ◽

Band Bending ◽

Test Cells

The changes of defect characteristics induced by accelerated lifetime tests on solar cells of the heterostructure ZnO/CdS/Cu(In,Ga)(S,Se)2/Mo are investigated. Encapsulated modules were shown to be stable against water vapor and oxygen under outdoor conditions, whereas the fill factor and open-circuit voltage of non-encapsulated test cells are reduced after prolonged damp heat treatment in the laboratory, leading to a reduced energy conversion efficiency. We subjected non-encapsulated test cells to extended damp heat exposure at 85 ◦C ambient temperature and 85% relative humidity for various time periods (6 h, 24 h, 144 h, 294 h, and 438 h). In order to understand the origin of the pronounced changes of the cells, we applied temperature-dependent current-voltage and capacitance voltage measurements, admittance spectroscopy, and deep-level transient spectroscopy. We observed the presence of electronic defect states which show an increasing activation energy due to damp heat exposure. The corresponding attempt-to-escape frequency and activation energy of these defect states obey the Meyer-Neldel relation. We conclude that the response originates from an energetically continuous distribution of defect states in the vicinity of the CdS/chalcopyrite interface. The increase in activation energy indicates a reduced band bending at the Cu(In,Ga)(S,Se)2 surface.We also observed changes in the bulk defect spectra due to the damp-heat treatment. - PACS: 73.20.hb, 73.61.Le

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Electrochemical and Oxidation Behavior of Yttria Stabilized Zirconia Coating on Zircaloy-4 Synthesized via Sol-Gel Process

International Journal of Corrosion ◽

10.1155/2013/453835 ◽

2013 ◽

Vol 2013 ◽

pp. 1-9 ◽

Cited By ~ 6

Author(s):

S. Rezaee ◽

Gh. R. Rashed ◽

M. A. Golozar

Keyword(s):

Heat Treatment ◽

Electrochemical Impedance ◽

Sol Gel ◽

Dip Coating ◽

Open Circuit ◽

Treatment Temperature ◽

Yttria Stabilized Zirconia ◽

Coated Sample ◽

Stabilized Zirconia ◽

Temperature Oxidation

Sol-gel 8 wt.% Yttria Stabilized Zirconia (YSZ) thin films were prepared on zirconium (zircaloy-4 alloy) by dip-coating technique followed by heat treating at various temperatures (200°C, 400°C, and 700°C) in order to improve both electrochemical corrosion and high temperature oxidation properties of the substrate. Differential thermal analysis and thermogravimetric analysis (DTA-TG) revealed the coating formation process. X-ray diffraction (XRD) was used to determine the crystalline phase structure transformation. The morphological characterization of the coatings was carried out using scanning electron microscopy (SEM). The electrochemical behavior of the coated and uncoated samples was investigated by means of open circuit potential, Tafel, and electrochemical impedance spectroscopy (EIS) in a 3.5 wt.% NaCl solution. The homogeneity and surface appearance of coatings produced was affected by the heat treatment temperature. According to the corrosion parameters, the YSZ coatings showed a considerable increase in the corrosion resistance, especially at higher heat treatment temperatures. The coating with the best quality, from the surface and corrosion point of view, was subjected to oxidation test in air at 800°C. The coated sample presented a 25% reduction in oxidation rate in comparison with bare substrate.

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Electrochemical Assessment of X70 Steel With Non-Conventional Heat Treatment

MRS Advances ◽

10.1557/adv.2017.518 ◽

2017 ◽

Vol 2 (50) ◽

pp. 2819-2829

Author(s):

L. R. Jacobo ◽

R. García ◽

V.H. López ◽

A. Contreras

Keyword(s):

Heat Treatment ◽

Charge Transfer ◽

Charge Transfer Resistance ◽

Open Circuit ◽

Polarization Curves ◽

Localized Corrosion ◽

Transfer Resistance ◽

Internal Corrosion ◽

Conventional Heat Treatment ◽

A Charge

ABSTRACTCorrosion behavior of an API X70 steel by potentiodynamic polarization curves was carried out. X70 steel was heat treated at a temperature of 1050°C (onset temperature solution of niobium carbonitrides) for 15 and 30 minutes hold followed by quenching in water. Test solutions for electrochemical evaluation were NS4 solution and congenital water (CW) to assess external and internal corrosion pipelines respectively. The polarization curves were performed within a range of -500mV to 1000mV for NS4 solution and the -500mV to 600mV by congenital water respect to open circuit potential (OCP) at a scan rate of 1mV/s. The tests were conducted at room temperature. The surfaces of the samples were observed by scanning electron microscope (SEM). A localized corrosion type was observed. According to polarization curves it can be observed that oxidation reaction in the anodic branch belongs to a charge transfer process. Cathodic branches reveal a process where the charge transfer resistance is influenced by a process of mass transfer. The non-conventional heat treatment improved the corrosion resistance compared to as received material.

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Magnetic coupling coefficient determination of IPT systems under operating conditions

Wireless Power Transfer ◽

10.1017/wpt.2014.10 ◽

2014 ◽

Vol 1 (2) ◽

pp. 83-86 ◽

Cited By ~ 1

Author(s):

A. Abdolkhani ◽

A.P. Hu

Keyword(s):

Real Time ◽

Coupling Coefficient ◽

Short Circuit ◽

Magnetic Coupling ◽

Short Circuit Current ◽

Open Circuit ◽

Operating Conditions ◽

Quality Factors ◽

Coupling Condition ◽

Coupled Coils

This study presents a method of determining the magnetic coupling coefficient of inductive power transfer (IPT) systems under real-time operating conditions by measuring the open-circuit voltage and short-circuit current of coupled coils. Besides the theoretical analysis, the proposed method is verified by finite elements simulation and practical evaluation. Both simulation and experimental results have demonstrated that the proposed method can determine the coupling coefficient of both closely and loosely coupled coils with high-quality factors. The method can be used for online monitoring of the coupling condition and real-time power flow controller design of IPT systems.

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Effects of Heat Treatments on Corrosion Behavior of Mg AT72 Alloy

Materials Science Forum ◽

10.4028/www.scientific.net/msf.747-748.230 ◽

2013 ◽

Vol 747-748 ◽

pp. 230-237 ◽

Cited By ~ 1

Author(s):

Zhi Qin Wang ◽

De Jiang Li ◽

Xiao Qin Zeng ◽

Xiao Mei Wu ◽

Wen Jiang Ding

Keyword(s):

Heat Treatment ◽

Hydrogen Evolution ◽

High Vacuum ◽

Treatment Method ◽

Optical Microscope ◽

Heat Treatments ◽

Open Circuit ◽

Second Phase ◽

Corrosion Properties ◽

Phase Phase

The effects of heat treatments, including T4, T5, T6 treatments, on corrosion behaviors of Mg-7Al-2Sn (AT72) alloy processed by high vacuum die casting have been investigated. The optical microscope, scanning electron microscope observations were used to analyze the microstructures, especially the distribution of second phase, phase contents and grain size. The hydrogen evolution tests, electrochemical methods including open circuit potential curves and polarization curves were used to describe the corrosion properties as well. The results indicated that different heat treatments had influence on microstructures, especially distribution of second phase, phase contents and grain sizes. The existence of second phase had a relationship with corrosion properties, in which the as-cast samples showed low corrosion rate in hydrogen evolution tests while the heat treatment methods had little impact on improving corrosion resistance. The electrochemical analyses also agreed with this observation. Based on these results, the optimized heat treatment method for corrosion resistant AT72 magnesium alloy has been established.

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Comparison of Corrosion Resistance of High Pressure Die-Cast and Semi-Solid Cast AZ91, AM60, Alloys and Respective Anodic Oxides

Materials Science Forum ◽

10.4028/www.scientific.net/msf.765.618 ◽

2013 ◽

Vol 765 ◽

pp. 618-622

Author(s):

Carmine Genoni ◽

Anna da Forno ◽

Massimiliano Bestetti

Keyword(s):

Heat Treatment ◽

Aqueous Solution ◽

High Pressure ◽

Corrosion Resistance ◽

Open Circuit Potential ◽

Open Circuit ◽

Environment Friendly ◽

Die Cast ◽

Cast Alloys ◽

Semi Solid

A comparison of corrosion resistance of die-cast and semi-solid cast AZ91and AM60 magnesium alloys was performed in corrosive medium by measurement of the open circuit potential and potentiodynamic scans. Before testing, a heat treatment was carried out on the semi-solid cast alloys. Moreover, electrochemical measurements were performed on the four different substrates anodized in the micro-arc regime in an environment friendly alkaline aqueous solution. The results could be correlated to the different microstructures of the samples produced by the different processes and to the different compactness/porosity of the oxides.

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An improved conventional Se–CdO photovoltaic cell

Canadian Journal of Physics ◽

10.1139/p85-123 ◽

1985 ◽

Vol 63 (6) ◽

pp. 767-771 ◽

Cited By ~ 23

Author(s):

C. H. Champness ◽

K. Ghoneim ◽

J. K. Chen

Keyword(s):

Heat Treatment ◽

Direct Current ◽

Annealing Temperature ◽

Open Circuit Voltage ◽

Reactive Sputtering ◽

Photovoltaic Cell ◽

Open Circuit ◽

Selenium Film ◽

Extra Oxygen

Studies previously carried out to improve the Se–CdO photovoltaic cell have emphasized optimization of the deposition of the CdO by direct current (DC) reactive sputtering. Attention has now been turned towards improving the deposition, doping, and heat treatment of the polycrystalline selenium base. It has been found that heat treatment of the selenium film on its substrate of aluminum and bismuth in air or oxygen prior to CdO deposition results in an increase in the illuminated open-circuit voltage (Voc) of the cell. The effect increased with increase of annealing temperature from 150 to 195 °C and in going from dry to wet oxygen. No increase in Voc was found by heating in nitrogen. The effect could be due to the formation of higher stoichiometric and hence higher resistivity CdO at the Se–CdO junction, arising from the presence of extra oxygen on the selenium surface.

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Corrosion Behaviour of High Pressure Die-Cast and Semi-Solid Cast AZ91, AM60 and AM50 Alloys

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.192-193.231 ◽

2012 ◽

Vol 192-193 ◽

pp. 231-237 ◽

Cited By ~ 3

Author(s):

Simone Umberto Mariani ◽

Anna da Forno ◽

Massimiliano Bestetti

Keyword(s):

Heat Treatment ◽

High Pressure ◽

Corrosion Resistance ◽

Open Circuit Potential ◽

Corrosion Behaviour ◽

Open Circuit ◽

Corrosive Media ◽

Die Cast ◽

Cast Alloys ◽

Semi Solid

A comparison of corrosion resistance of die-cast and semi-solid cast AZ91, AM60 and AM50 magnesium alloys was performed in different corrosive media by measurement of the open circuit potential, potentiodynamic scans and weight loss tests. Before testing, a heat treatment was carried out onto semi-solid cast alloys. Electrochemical measurements have shown that the semi-solid cast alloys have a different corrosion rate compared to the die-cast ones. The results could be correlated to the different microstructures of the samples produced by the different processes.

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