scholarly journals Rare Earth Cerium Increases the Corrosion Resistance of NdFeB Magnets

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4360
Author(s):  
Jialei Dai ◽  
Zixuan Yang ◽  
Qian Liu
Keyword(s):  
Corrosion Resistance ◽  
Metal Matrix ◽  
Kelvin Probe ◽  
Rich Phase ◽  
Impact Mechanism ◽  
Ndfeb Magnets ◽  
Electrochemical Tests ◽  
Force Microscopy ◽  
The Impact ◽  
Ce Content

Herein, we investigated the effects of Ce on the corrosion behavior of NdFeB magnets in 3.5% NaCl solutions using electrochemical tests, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) mapping, and scanning Kelvin probe force microscopy (SKPFM). We demonstrated that Ce markedly enhances the corrosion resistance of NdFeB magnets. Ce primarily replaces Nd in the Nd-rich phase instead of matrix phase, increasing the surface potential of the Nd-rich phase. An increase in the Ce content from 0 to 5.21 wt%, decreased the potential difference between the main phase and (Nd, Ce)-rich phase from 350.2 mV to 97.7 mV; therefore, the corrosion resistance of the magnetic materials increased. The corrosion resistance constituted the Nd-rich phase < the void < metal matrix. Moreover, based on the results of the study, we discussed the impact mechanism of additions of Ce on the corrosion resistance of the magnets.

scholarly journals The role of chromium content in the long-term atmospheric corrosion process

2020 ◽  
Vol 4 (1) ◽  
Author(s):  
Baozhuang Sun ◽  
Xiaomei Zuo ◽  
Xuequn Cheng ◽  
Xiaogang Li
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Rate ◽  
Atmospheric Corrosion ◽  
X Ray Diffraction ◽  
Kelvin Probe ◽  
Electrochemical Tests ◽  
Force Microscopy ◽  
Cr Content ◽  
Alloy Steels ◽  
Bare Steel

AbstractThe corrosion of alloy steels with different amounts of Cr was studied using electrochemical tests, wet–dry cycle corrosion, X-ray diffraction, and Kelvin probe force microscopy. The results show that the content of Cr is positively correlated with the corrosion resistance of bare steel, but the corrosion resistance of atmospheric corrosion does not show the same pattern. The atmospheric corrosion resistance of Cr-containing steel exhibits three different stages with the change of Cr element content. When the Cr content is in the range of 1–4%, the corrosion rate is high and does not change within the Cr content. As the Cr content was further increased from 4 to 7%, the corrosion rate exhibited a linear decrease and then drops rapidly when the Cr content reaches 8%. These three different corrosion rate stages are related to the influence of Cr content on Fe3O4 content in the rust layer.

scholarly journals Glass-Forming Ability and Corrosion Resistance of Al88Y8−xFe4+x (x = 0, 1, 2 at.%) Alloys

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1581
Author(s):  
Rafał Babilas ◽  
Monika Spilka ◽  
Katarzyna Młynarek ◽  
Wojciech Łoński ◽  
Dariusz Łukowiec ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Analytical Techniques ◽  
Corrosion Current ◽  
Glass Forming Ability ◽  
Electrochemical Tests ◽  
Glass Forming ◽  
Transmission Electron ◽  
Composition And Structure ◽  
Amorphous Structures ◽  
The Impact

The effect of iron and yttrium additions on glass forming ability and corrosion resistance of Al88Y8-xFe4+x (x = 0, 1, 2 at.%) alloys in the form of ingots and melt-spun ribbons was investigated. The crystalline multiphase structure of ingots and amorphous-crystalline structure of ribbons were examined by a number of analytical techniques including X-ray diffraction, Mössbauer spectroscopy, and transmission electron microscopy. It was confirmed that the higher Fe additions contributed to formation of amorphous structures. The impact of chemical composition and structure of alloys on their corrosion resistance was characterized by electrochemical tests in 3.5% NaCl solution at 25 °C. The identification of the mechanism of chemical reactions taking place during polarization test along with the morphology and internal structure of the surface oxide films generated was performed. It was revealed that the best corrosion resistance was achieved for the Al88Y7Fe5 alloy in the form of ribbon, which exhibited the lowest corrosion current density (jcorr = 0.09 μA/cm2) and the highest polarization resistance (Rp = 96.7 kΩ∙cm2).

scholarly journals Inhibition Effect of 4-(2-Chlorophenyl)Hydrazineylidene-1-Phenyl-2-Pyrazolin-5-One Derivatives on Corrosion of 304 Stainless Steel in HCl Solution

2021 ◽  
Vol 11 (6) ◽  
pp. 14673-14687
Keyword(s):  
Stainless Steel ◽  
Electrochemical Impedance ◽  
Protective Layer ◽  
Outcome Data ◽  
304 Stainless Steel ◽  
Electrochemical Tests ◽  
Force Microscopy ◽  
The Impact ◽  
Ss 304 ◽  
Hcl Solution

4-(2-chlorophenyl)hydrazineylidene-1-phenyl-2-pyrazolin-5-one derivatives (2-CPH) were examined as safe corrosion hindrance for 304 stainless steel (SS 304) in 1.0 M HCl utilizing weight loss (WL) and electrochemical tests such as potentiodynamic polarization (PP), electrochemical impedance spectroscopy (EIS) and electrochemical frequency modulation (EFM). The outcome data displayed that the protection efficiency (IE%) rises with improving the dose of 2-CPH compounds and lower with raising the temperature. The adsorption of these inhibitors on the surface of SS 304 follows Langmuir isotherm. The 2-CPH are the best inhibitors for the dissolution of SS 304 in 1M HCl and they are mixed kind inhibitors. Quantum calculations (QM) display the impact of the chemical structure of the 2-CPH on its %IE. Additionally, 304 stainless surface topography in one molar HCl solution without and with 2-CPH compounds appending utilizing atomic force microscopy (AFM) approves the protection of 304 stainless via adsorbed 2-CPH compounds by a formed protective layer.

scholarly journals The impact of Kelvin probe force microscopy operation modes and environment on grain boundary band bending in perovskite and Cu(In,Ga)Se2 solar cells

Nano Energy ◽  
2021 ◽  
pp. 106270
Author(s):  
Evandro Martin Lanzoni ◽  
Thibaut Gallet ◽  
Conrad Spindler ◽  
Omar Ramírez ◽  
Christian Kameni Boumenou ◽  
...  
Keyword(s):  
Solar Cells ◽  
Grain Boundary ◽  
Kelvin Probe Force Microscopy ◽  
Kelvin Probe ◽  
Band Bending ◽  
Force Microscopy ◽  
Operation Modes ◽  
The Impact

scholarly journals Kelvin probe force microscopy work function characterization of transition metal oxide crystals under ongoing reduction and oxidation

2019 ◽  
Vol 10 ◽  
pp. 1596-1607
Author(s):  
Dominik Wrana ◽  
Karol Cieślik ◽  
Wojciech Belza ◽  
Christian Rodenbücher ◽  
Krzysztof Szot ◽  
...  
Keyword(s):  
Transition Metal ◽  
Metal Oxides ◽  
Work Function ◽  
Transition Metal Oxides ◽  
Lateral Resolution ◽  
Kelvin Probe ◽  
Force Microscopy ◽  
Reduction And Oxidation ◽  
The Impact

Controlling the work function of transition metal oxides is of key importance with regard to future energy production and storage. As the majority of applications involve the use of heterostructures, the most suitable characterization technique is Kelvin probe force microscopy (KPFM), which provides excellent energetic and lateral resolution. In this paper, we demonstrate precise characterization of the work function using the example of artificially formed crystalline titanium monoxide (TiO) nanowires on strontium titanate (SrTiO3) surfaces, providing a sharp atomic interface. The measured value of 3.31(21) eV is the first experimental work function evidence for a cubic TiO phase, where significant variations among the different crystallographic facets were also observed. Despite the remarkable height of the TiO nanowires, KPFM was implemented to achieve a high lateral resolution of 15 nm, which is close to the topographical limit. In this study, we also show the unique possibility of obtaining work function and conductivity maps on the same area by combining noncontact and contact modes of atomic force microscopy (AFM). As most of the real applications require ambient operating conditions, we have additionally checked the impact of air venting on the work function of the TiO/SrTiO3(100) heterostructure, proving that surface reoxidation occurs and results in a work function increase of 0.9 eV and 0.6 eV for SrTiO3 and TiO, respectively. Additionally, the influence of adsorbed surface species was estimated to contribute 0.4 eV and 0.2 eV to the work function of both structures. The presented method employing KPFM and local conductivity AFM for the characterization of the work function of transition metal oxides may help in understanding the impact of reduction and oxidation on electronic properties, which is of high importance in the development of effective sensing and catalytic devices.

scholarly journals The Microstructure and Mechanical and Corrosion Behaviors of Thermally Aged Z3CN20-09M Cast Stainless Steel for Primary Coolant Pipes of Nuclear Power Plants

Coatings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 870
Author(s):  
Fei Xue ◽  
Fangjie Shi ◽  
Chuangju Zhang ◽  
Qiaoling Zheng ◽  
Dawei Yi ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Aging Time ◽  
Thermal Aging ◽  
Great Influence ◽  
Fracture Mechanisms ◽  
Rich Phase ◽  
Corrosion Behaviors ◽  
The Impact ◽  
Cast Stainless Steel

The effects of thermal aging time at 400 °C on the microstructure and mechanical and corrosion behaviors of Z3CN20.09M cast stainless steel were investigated; and the corresponding thermal aging mechanism was studied. It was revealed that the changes in mechanical properties after thermal aging were mainly caused by the iron-rich phase (α) and the chromium-rich phase (α’) produced by the amplitude-modulation decomposition of ferrite. A similar trend of thermoelectric potential during thermal aging was determined in relation to the Charpy impact energy. However, the corrosion resistance of Z3CN20.09M cast stainless steel deteriorates as thermal aging time increases. When the thermal aging is longer than 3000 h, the precipitation of G phase has a great influence on the corrosion resistance. The interfacial matching relationship between G phase and the surrounding ferrite was established by selected area electron diffraction of HRTEM. The relationship is of cube-on-cube phase boundary type. The impact fracture mechanisms in relation to thermal aging time were also studied and compared.

A review on the corrosion resistance of electroless Ni-P based composite coatings and electrochemical corrosion testing methods

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Imtiaz Ahmed Shozib ◽  
Azlan Ahmad ◽  
Ahmad Majdi Abdul-Rani ◽  
Mohammadali Beheshti ◽  
Abdul’Azeez Abdu Aliyu
Keyword(s):  
Corrosion Resistance ◽  
Electrochemical Impedance ◽  
Composite Coatings ◽  
Electrochemical Corrosion ◽  
Kelvin Probe ◽  
Corrosive Media ◽  
Measuring Techniques ◽  
Electroless Ni ◽  
The Impact ◽  
Electrode Technique

Abstract This paper aims to review the impact of different factors influencing the corrosion resistance of electroless Ni-P based coatings. Emphasis has been given onto the impact of phosphorus content, incorporation of alloying elements, addition of particles and heat treatment which have been discussed in detail and critically reviewed. The effect of corrosive media and coating process parameters on corrosion resistance are studied concisely. Furthermore, the role of the incorporation of various elements and particles’ contents on the corrosion resistance of electroless Ni-P coating are studied systematically. This paper also presents an overview of the latest electrochemical corrosion measuring techniques. The following approaches deserve special attention in the analysis: localized electrochemical impedance spectroscopy (LEIS), scanning vibrating electrode technique (SVET), scanning ion-selective electrode technique (SIET), scanning droplet cell (SDC), scanning electrochemical microscopy (SECM), scanning Kelvin probe (SKP) and novel contactless technique (NCT).

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