bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of Representative Tests to Quantify the Susceptibility to Stress Corrosion Cracking of α,β’-Brass Used for Gas Transfer Devices
Authors: Berne Clément , Andrieu Eric , Reby Jean , Sobrino Jean-Michel , Blanc Christine 
Published: February 2020

Stress corrosion cracking (SCC) is believed to be the principal cause of the cracks observed in brass components used in gas distribution network. In this framework, it is of interest to develop accelerated tests to determine the SCC susceptibility of the brass used in the gas transfer valves. To be representative and reliable, a reference test has to reproduce most of the damages observed on network components after break-up during operation. The present study aimed at developing SCC equipment and experimental protocol leading to a relevant evaluation of the SCC susceptibility of α,β’-brass.
The specimens tested, corresponding to α,β’-brass CuZn40Pb2 (CW617N), were machined from stamping rods used to manufacture gas transfer valves. The accelerated tests were performed in NaNO3 solution selected with reference to research on α-brass (1). The first step of the study corresponded to develop a SCC cell and an adequate experimental protocol, which enable to apply, control and measure specific conditions (load, potential, environment…) leading to various SCC damages; the second step was to compare the SCC damage developed after the accelerated tests to that observed on network components after break-up during operation. The goal was to determine the best parameters for the accelerated tests leading to a SCC damage similar to that observed in service.
Results correspond to the design of the SCC cell developed and the methodology used to validate the applied conditions, and the measurements performed through SCC device. Furthermore, SCC damage developed after the tests was studied on the basis of crack characterisation, quantification of the dissolution process and chemical analyses of the corroded samples. Discussion focuses on the validity and the predictive nature of the test, linked to environment and load levels expected in normal condition of use of brass network components (2) (3). The influence of the manufacturing of brass network components on the SCC susceptibility (modifications in microstructure, work hardening and residual stresses) will be discussed and, in this way, prospects will be presented.
1. S.A. Fernandez and M.G. Alvarez, Corros. Sci.,
53, 82 (2011).
2. C. Mapelli, A. Gruttaduaria and M. Bellogini, Eng. Fail. Anal.,
17, 431 (2010).
3. C. Mapelli, D. Mombelli, S. Barella and A. Gruttadauria, Eng. Fail. Anal.,
27, 141 (2013).
Micro-Arc Oxidation Treatments on Zn
Authors: Veys-Renaux Delphine , Guessoum Khadoudj , Rocca Emmanuel 
Published: February 2020

Micro-arc oxidation has been a hot topic in the field of surface treatment of aluminum, magnesium and titanium for about twenty years. It consists in a high-voltage oxidation beyond the dielectric breakdown occurring at the interface metal/oxide/electrolyte. Due to the high temperature reached in the resulting plasma, the grown coatings are dry ceramic layers, exhibiting interesting corrosion and wear resistance. This process is generally performed in alkaline media containing additives favoring both the growth rate and the corrosion resistance of the coated materials such as aluminates and silicates. This original paper focuses on the study of micro-arc treatments performed on zinc [1], which could lengthen the service life of sacrificial anodes.
An electrochemical study during the anodizing process revealed that the formation of the first stable insulating layer necessary to reach the dielectric breakdown (and therefore to initiate the sparks) is in competition with the dissolution of zinc. Therefore, beyond a maximum value of pH, starting with the micro-arc regime is no more possible. On the other hand, the addition of silicates or aluminates to the reference electrolytic bath (KOH 0.05 M) facilitates the occurrence of the sparking initiation: around 200 V in KOH 0.05 M, around 150 V with aluminates 0.05 M, around 100 V with silicates 0.05 M.
Post-treatment characterizations of the treated materials performed by FEG-SEM observations coupled with EDX analyses showed that the thickness, the morphology and the composition of the coatings highly depend on the composition of the electrolytic bath.
In terms of corrosion resistance, open-circuit potential measurements, potentiodynamic polarizations and electrochemical impedance spectroscopy measurements were performed in NaCl 0.1 M and showed a very slight improvement of the performances of the treated materials regarding an untreated one since the obtained coatings are cracked and dusty.
[1] TR. Tan, JR. Cheng, JH.Wang, JG Duh, HC. Shih, Surf. Coat. Tech 110, 194-199 (1998)
Electrochemical and Microstructural Study of 18th Century Cannon Ball
Authors: Mortera-Merino Juvencio , Galvan-Martínez Ricardo , Orozco-Cruz Ricardo 
Published: February 2020

The main degradation phenomena that affect the metallic cultural heritage are the corrosion reactions with its environment: the burial soil, the outdoor atmosphere or the indoor environment of the museum, display cases or storage. The best way to avoid, or at least delay, such degradation is through preventive conservation. (1)

The conservation and restoration of archaeological metals is one of the most complex conservation issues. Therefore, conservators usually employ the most advanced techniques, with the purpose of obtaining positive results for the preservation of the objects. (2-3)

Nowadays, electrochemical techniques are provided with control devices, such as potentiostatic control and could be considered again as a very valuable option, in combination with traditional and vanguard techniques, to recover the archaeological metallic heritage.(4)

The objective of this work is to show how electrochemical measurements and microstructural characterization can be used as an efficient tool to contribute to the diagnosis of the conservation state of metallic artefacts. In the case of the cannon ball, In San Juan de Ulua Fortress, stationary electrochemical measurements are able to characterise the allowable electrochemical effect of thick corrosion layer on the corrosion rate of metal but are not sufficient to give a complete diagnosis.
The electrochemical behavior of a cannon ball has been studied in two media: 0.01 M sodium borate and 1M sodium chloride. Techniques used include potential measurements as function of time, linear polarization resitance, potentiodynamic polarization curves and electrochemical impedance spectroscopy.
These techniques were carried out on cannon ball fragment, in order to relate microstructural aspects with functionality, manufacturing technology of the piece. Metallographic characterization was performed by optical microscopy and scanning electron microscopy, and chemical analysis by energy dispersive X-ray spectrometry. The results allowed determining that the piece was of lamellar grey iron. (5-7)

The obtained data suggest a relationship between alloy composition and electrochemical properties of the material.
Scanning Kelvin Probe Force Microscopy as Tool for the Investigation of Localized Corrosion
Authors: Rohwerder Michael 
Published: February 2020

In this presentation it will be shown that the Scanning Kelvin Probe Force Microscopy (SKPFM) is a powerful tool for the characterization of corrosion processes at the microscopic level, especially underneath organic coatings, see e.g. [1-3], but also on the uncoated surface, see e.g. [4].
Recently it was developed also to detect hydrogen activity in metal alloys at high resolution and sensitivity and [5-7] and it will be shown that it thus can be applied for the investigation also of hydrogen induced corrosion phenomena.
[1] M. Rohwerder, E. Hornung, M. Stratmann, Electrochim. Acta 48 (2003) 1235
[2] C. Senöz, M. Rohwerder, Electrochim. Acta 56 (2011) 9588
[3] C. Senöz, S. Borodin, M. Stratmann, M. Rohwerder, Corros. Sci. 58 (2012) 307
[4] D.B. Blucher, J.E. Svensson, L.G. Johansson, M. Rohwerder, M. Stratmann, J. Electrochem. Soc. 151 (2004) B621
[5] C. Senöz, S. Evers, M. Stratmann and M. Rohwerder, Electrochem. Commun. 13 (2012)1542
[6] S. Evers, M. Rohwerder, Electrochem. Commun. 24 (2012) 85
[7] S. Evers, S. Ceylan, M. Rohwerder, Science and Technology of Advanced Materials 14 (2013) 014201
Volta Potential on Stainless Steel Under Mechanical Stress Conditions
Authors: Casals Nuria , Nazarov Andrej , Thierry Dominique 
Published: February 2020

It is well documented fact that mechanical work or surface treatment creates stresses in the metal. In corrosive environment the stress can lead to stress corrosion cracking and failure of the metal construction. It is often supposed that stress influences the properties of the surface oxide film by creating defects like metal vacancies and thus activating the anodic dissolution. On the other hand, the kinetic of the partial corrosion reactions is determined by the local electrochemical potential. Thus it is important to know how the stress influences on the surface potential.
The aim of the present study was to measure the influence of stress on the electrochemical potential of stainless steel 301 grade in situ under loading using Scanning Kelvin Probe. The measurements were carried out in the laboratory air at 50%RH and the measured Volta potential was related to the potential of the steel in the passive state. Previously this kind of measurements was carried out elsewhere [A. Nazarov, D. Thierry "Application of Volta potential mapping to determine metal surface defects",Electrochimica Acta 52 (2007) 7689-7696.].
In this work a constant load cell was applied on the sample with notches that concentrates the stress in a particular location. The load was measured and it was in the elastic or plastic deformation range. It was found that elastic deformation resulted in rather low potential changes whereas plastic deformation decreased the surface potential.
Figure 1: A: Potential profile in the notched area, B: Impact of the compressive stress produced by indentation.
Figure 1A shows the potential profile for the steel surface in the notched area under tensile stress conditions. Figure B shows the impact of the compressive stress produced by indentation.
It is possible to conclude that stress decreased the surface potential of the steel by about 200-300 mV. Thus the stress decreased the level of metal passivity that can facilitate the local anodic dissolution. After unloading under residual stress conditions the surface very slowly shifted the potential to the initial level. The effect of the plastic deformation on the steel potential is explained on the basis of the formation of dislocations and defective oxide film. The surface analytical studies are in progress.
Copper-Nanolaminate Composites – a New and Promising Material for Electrical Contacts in High Voltage and High Current Applications
Authors: Grieseler Rolf , Camargo Magali Karina , Hopfeld Marcus , Bund Andreas , Schaaf Peter 
Published: February 2020

Nanolaminate Mn+1AXn phases [1], [2] are materials that show interesting properties. They exhibit high hardness as well as good thermal and chemical stability, which is commonly a ceramic like behavior. On the other hand, they are good conducting materials near the range of metals.
Electrical contacts used in high voltage and high current applications are commonly based on silver-tin dioxid (Ag-SnO) where the SnO is used to increase the durability of the silver contact [3]. Futhermore the silver might be doped or alloyed with other materials such as tungsten or cadmium. The contact material is produced by powder metallurgical approach.
Lately the prices of noble metals are increasing and therefore, the pursuit of finding alternative possibilities is leading to new approaches and materials.
A promising approach is the electrochemical deposition of copper – nanolaminate composites. Two different types of Mn+1AXn phase were chosen as hard particles. One was Ti2AlC from the 211 Mn+1AXn phase family and the second was Ti3SiC2 from the 312 Mn+1AXn phase group. Particles of these two materials (mean size: aprox. 2 µm) were co-deposited with copper to form an electrical conductive surface with higher hardness than common copper. The distribution of the particles was determined using Focused Ion Beam cross section. The behavior at high currents and high voltages as well as in electrical discharges was investigated.

References:
[1] M. W. Barsoum, “The MN+1AXN phases: A new class of solids,” Prog. Solid State Chem., vol. 28, no. 1–4, pp. 201–281, Jan. 2000.
[2] R. Grieseler, T. Kups, M. Wilke, M. Hopfeld, and P. Schaaf, “Formation of Ti2AlN nanolaminate films by multilayer-deposition and subsequent rapid thermal annealing,” Mater. Lett., vol. 82, pp. 74–77, Sep. 2012.
[3] N. Jeanvoine, C. Selzner, F. Soldera, and F. Muecklich, “In situ FIB-Surface Preparation of Ag/SnO Composites for EBSD Measurements,” Microsc. Microanal., vol. 13, no. S02, Aug. 2007.
Electrodeposition of Nanoscale Manganese Oxide for Electrochemical Energy Storage Devices
Authors: Clark Michael Patrick , Ivey Douglas G , Qu Wei 
Published: February 2020

As society moves away from fossil fuels towards renewable energy sources, energy storage is becoming increasingly important. Manganese oxide is a good candidate material for multiple energy storage applications (e.g., rechargeable batteries and supercapacitors) because it is environmentally benign and has good catalytic and electrochemical properties. When used as a supercapacitor, manganese oxide stores charge through electric double layer and redox effects. To maximize these effects, the structure of manganese oxide deposits needs to be optimized; this means increasing the effective surface area of the deposit. In addition to the effective surface area, the crystal structure of the deposit also greatly affects both catalytic and electrochemical performance. Manganese oxide is polymorphic and it is important to understand the crystallography of the manganese oxide within a device, in order to optimize its properties.
In this work, nickel foam is coated with high surface area manganese oxide through a simple anodic electrodeposition procedure. Nickel foam is an excellent substrate for many energy storage devices because in addition to nickel’s good conductivity, the porosity of the foam increases surface area and also facilitates fluid flow through the substrate. The latter is important for applications where manganese oxide is being used as a catalyst.
The electrolyte used for deposition of manganese oxide contains manganese acetate, ammonium acetate and dimethyl sulfoxide. By varying deposition and post deposition annealing conditions, different microstructures are obtained. The microstructure, crystallography and chemical state of the manganese oxide deposits are characterized through scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). XPS analysis has been used to determine that manganese oxide is in the form of MnO2. Preliminary XRD and TEM results indicate that the deposits obtained in this work are nanocrystalline with grains less than 20 nm in size.
Electrochemical tests such as cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) are used to determine performance (e.g., capacitance and cyclability) and to optimize the morphology and structure of the manganese oxide deposits. Preliminary CV measurements suggest that the manganese oxide deposits on nickel foam exhibit good areal and specific capacitance.
LiCoO2 Thin Film Deposition Using a Low-Temperature Electrochemical-Hydrothermal Route
Authors: Azib Tahar , Lecras Frédérique , Porthault Hélène 
Published: February 2020

The increasing miniaturization of electronic devices and the demand for stand-alone systems require adapted power sources in terms of dimensions and energy. All-solid-state microbatteries are an interesting solution for new applications (secured smart cards, medical implants, sensors, etc.). They are obtained by successive deposition of thin films of electrode active materials and solid electrolyte. However, these batteries have a rather low capacity (50-200 µAh/cm²) due to the difficulty to use electrodes thicker than 5µm (electronic conductivity, lithium diffusion and mechanical stress issues). Most of commercially available microbatteries use a LiCoO2 positive electrode due to its interesting properties: a 4V/Li+/Li nominal voltage, an excellent cycle life and a high electronic conductivity [1] . Thin films of LiCoO2 are mainly obtained by sputtering [2, 3] , followed by an annealing (500-700°C) necessary to obtain the electrochemically active phase of LiCoO2 (R-3m). This latter step then limits the possible substrates. Moreover the low deposition rate (10nm/mn) and the required equipments and facilities make this process quite costly.
To circumvent these drawbacks, thin films of LiCoO2 were synthesized by a novel single-step route: the electrochemical-hydrothermal deposition. This technique combines the effects of the hydrothermal conditions (temperature and pressure) with a galvanostatic electrodeposition. Using ethanol as co-solvent in the aqueous media, we succeded in obtaining a pure and highly-crystalline LiCoO2 films, without any Co3O4 impurity. Moreover, the surface roughness is greatly decreased (fig.1) compared with films obtained in pure aqueous media. The obtained thickness can be increased up to 30µm, equal to a deposition rate of 200nm/mn. Galvanostatic cycling and linear sweep voltammetry experiments were carried out on these electrodes using CR2032 coin cells. The electrochemical properties of these films are very promising and clearly evidence the influence of each deposition parameter (temperature, current density, water/ethanol ratio, etc.) (fig2).

[1] Reimers, J.N. and J.R. Dahn, Journal of the Electrochemical Society, 1992. 139(8): p. 2091-2097.

[2] Wei, G., T.E. Haas, and R.B. Goldner, Solid State Ionics, 1992. 58(1-2): p. 115-122.

[3] Wang, B., et al., Journal of the Electrochemical Society, 1996. 143(10): p. 3203-3213.
The 14 Year Path of Lithium-Ion Stacking Power Battery at Amita Technologies
Authors: Cherng Jing-Yih 
Published: February 2020

Since the commercialization of lithium-ion batteries in 1990, the applications of lithium-ion batteries have spread in a speed faster than any other battery systems. Pouch lithium-ion cells are becoming popular since the year of 2000. In the beginning, the Bellcore type design and process were used and troubled by internal short circuit and other problems. Afterwards, regular winding designs were used for most of pouch cells for 3C applications. Latest, the stacking design and process were introduced to the pouch cells for the high power applications, especially, the EV applications.
Amita technologies is one of the companies, who introduced the stacking pouch lithium-ion cells into the power applications in the year of 2000. In order to make thinner and safer lithium-ion stacking power cells, quite a few processes are different from the winding processes. Since the new process manufacturing equipments were not available in the year of 2000, Amita not only need to verify the cell design and process also need to design her own manufacturing equipment. From electrode cutting machine, stacking machine, welding machine, electrolyte injection machine, to the conveyor formation system. The development of an automation manufacturing system was completed in 2010. In 2014, the 2nd generation automation system is being designed and will be set up with a higher efficiency and a better consistency in 2015.
Because of the development of EV and renewable energy, it is the interest of many countries to set up its own lithium-ion battery industry. Amita has developed an unique manufacturing model (PDCA, post dry-cell assembly) , by utilizing her own patented design and processes, through which dry cells can be easily made and stored and shipped. PDCA can greatly reduce the difficulties of setting up a lithium-ion battery factory. Since all the materials except the electrolyte have been included in the dry cells, not only the dry cells can be easily made into real cells in the customer side, also the dry cells are perfectly safe to ship and store. Plus, the investment of PDCA becomes less than one fifth of the total production line, and has many other advantages. Unique features of PDCA will be illustrated and explained in details during the presentation.
Electrolyte Circulation in Copper Refinery
Authors: Fukunaka Yasuhiro 
Published: February 2020

The importance of natural convection accompanied with electrochemical reactions along vertical electrodes has been recognized in the field of industrial electrochemical engineering as well as electrodeposition. Brenner applied a freezing method to analyze the concentration distribution[1]. Wagner demonstrated that the limiting current density distribution along the vertical cathode was governed by natural convection, based on the boundary layer theory [2, 3]. Wilke, Eisenberg and Tobias described a similarity between the natural convection caused by electrodeposition and by heat transfer [4]. Ibl and Muller examined the ionic mass transfer rate by the interferometry technique [5]. Since then, numerous studies have been carried out on the ionic mass transfer rate associated with natural convection caused by the electrochemical deposition and dissolution of copper in unstirred CuSO4-H2SO4aqueous electrolyte solutions [6-15]. However, most studies have focused on the steady state phenomena along a relatively short electrode at most 15 cm high confined in semi-infinite electrolyte media and have neglected the effects caused by the existence of the counter electrode.
In industrial scale of copper refinery, vertical impure casted anode and starting sheet of electrolytic copper cathode are installed in the tank. Significant electrolyte stratification may frequently cause various troubles to induce poor cathode quality. Each refinery designs their own electrolyte circulation system with their confidence. Additive control technique is a key technology. Sometime a slightly different circulation system is introduced even in one refinery in the same company. It is simply because the principle of electrolyte circulation has been never discussed from the fundamental electrochemical engineering point. It may be a starting point for this problem in such a modernized computational technology.