Nickel Sheet Research Articles

Flow stress improvement of a nickel multicrystal by physical vapor thin film deposition to reduce surface effects

Uniaxial tensile tests were carried out on nickel sheets containing only few grains across the thickness thus presenting a so-called multicrystalline state. Pristine sheets used as reference and substrates covered by a nickel layer deposited by physical vapor deposition (magnetron sputtering) were studied. Results attest that the surface treatment affects the plastic deformation mechanisms by playing the role of a blocking barrier to dislocation movement which leads to a significant improvement of mechanical performances. The surface restructuring of the nickel sheets is efficient to stop dislocation escape through free surfaces and allows a mechanical improvement of the well-known strong mechanical softening of the multicrystals.

Effect of Substrate on the Performance of Flexible Energy Storage Devices based on Surface Modified C60– β Ni(OH)2 Nanocomposite

Aim: Aim of this study is to find the effect of the current collector on the performance of flexible energy storage devices based on surface modified organic-inorganic composite. Objective: As a part of our pursuit to develop flexible supercapacitive electrodes, we recently reported the fabrication of an electrode from an organic-inorganic composite slurry of surface functionalized fullerene and nickel hydroxide coated onto a copper sheet substrate using simple doctor blade method. We reported that the electrodes deliver specific energy and specific power of 661.5 Wh/kg and 8.8 KW/kg, respectively, and a specific capacitance of 675 Fg−1, which showed excellent cycling stabilities. In an effort to search for various combinatorial combinations of the composite and the substrate, in lieu of copper, in the present study, we incorporate nickel sheet as the current collector. Methods: The structure and composition of the binder-free, flexible, super capacitive electrodes were characterized using XRD, TEM, FTIR, XPS, BET, Raman Spectroscopy, and their electrochemical properties were characterized using cyclic voltammetry, galvanostatic charge-discharge measurements, chronoamperommetry and impedance spectroscopy. Result: The as-prepared films stuck readily onto the substrate without the need for any binder material, exhibited remarkable flexibility, and were proven to be crack-free when subjected to repeated bending and twisting. The developed flexible, super capacitive electrodes deliver a specific capacitance of 296 F g−1, maximum energy density of 82.2 Wh kg−1, and a maximum power density of 1056 W kg−1. The device retains 91.2 % of its capacitance when subjected to 1000 charge-discharge cycles. Conclusion: Our observations indicate that copper is the better choice as the current collector, which can be ascribed to the better electrical conductivity of copper compared to nickel. We conclude that the poor electrical conductivity of nickel sheet compared to copper substrate make the bottleneck for the performance of electrodes made using nickel substrate. To recapitulate, a judicious choice of a current collector with high electrical conductivity along with a suitable surface modification strategy to form a composite in an amorphous form that forms smooth slurry are vital to the fabrication of binder-free, flexible supercapacitive devices.

Underfocus Laser Induced Ni Nanoparticles Embedded Metallic MoN Microrods as Patterned Electrode for Efficient Overall Water Splitting.

Transition metal nitrides have shown large potential in industrial application for realization of the high active and large current density toward overall water splitting, a strategy to synthesize an inexpensive electrocatalyst consisting of Ni nanoparticles embedded metallic MoN microrods cultured on roughened nickel sheet (Ni/MoN/rNS) through underfocus laser heating on NiMoO4·xH2O under NH3 atmosphere is posited. The proposed laser preparation mechanism of infocus and underfocus modes confirms that the laser induced stress and local high temperature controllably and rapidly prepared the patterned Ni/MoN/rNS electrodes in large size. The designed Ni/MoN/rNS presents outstanding catalytic performance for hydrogen evolution reaction (HER) with a low overpotential of 67 mV to deliver a current density of 10 mA cm−2 and for the oxygen evolution reaction (OER) with a small overpotential of 533 mV to deliver 200 mA cm−2. Density functional theory (DFT) calculations and Kelvin probe force microscopy (KPFM) further verify that the constructed interface of Ni/MoN with small hydrogen absorption Gibbs free energy (ΔG H*) (−0.19 eV) and similar electrical conductivity between Ni and metallic MoN, which can explain the high intrinsic catalytic activity of Ni/MoN. Further, the constructed two‐electrode system (−) Ni/MoN/rNS||Ni/MoN/rNS (+) is employed in an industrial water‐splitting electrolyzer (460 mA cm−2 for 120 h), being superior to the performance of commercial nickel electrode.

Study on the bonding mechanism of multilayer copper with nickel sheet in ultrasonic welding process

The metal-plastic flow and bonding strength of three-layer copper (Cu) with single-layer nickel (Ni) joints via ultrasonic welding were investigated in this study. With the increase of welding time from 0.3 to 0.5 s, the weld bonding density between different layers’ interface increased gradually and approached about 95 ± 1.5%. Electron backscatter diffraction (EBSD) analysis of different regions of the welded joint revealed that the metal grains in the 1st layer became relatively small and elongated, while the 2nd and 3rd layers tended to be equiaxed grains. The joint bonding strength of T-peel tests changed with welding time and had two kinds of fracture models (nugget pullout and interfacial fracture). Compared with the bonding strength of the 1st-2nd and 3rd-4th interface, the 2nd-3rd interface of joints had the highest bonding strength of 400.6 N with nugget pullout fracture model at welding time of 0.4 s. In addition, the much higher hardness of the 1st layer is attributed to the strong plastic deformation of the 1st layer, while the dynamic recovery and dynamic recrystallization of the metal of the 2nd layer resulted in the decrease of hardness.

Efficient preparation of Ni-M (M = Fe, Co, Mo) bimetallic oxides layer on Ni nanorod arrays for electrocatalytic oxygen evolution

Fabrication of economic and high-performance electrodes for electrocatalytic oxygen evolution reaction (OER) accounts for a crucial issue associated with developing powerful and practical water splitting systems. In this work, free-standing Ni/Ni-M (M = Fe, Co, Mo) bimetallic oxides core/shell nanorod arrays (Ni/Ni-M NRAs) were prepared through electroless deposition of transition metal species on black nickel sheet (nickel nanorod arrays (Ni NRAs)) followed by electrochemical oxidation. All three types of Ni/Ni-M NRAs demonstrated enhanced electrocatalytic activity toward oxygen evolution reactions (OER). Especially, Ni/Ni-Fe NRAs electrode exhibit small onset potential of 1.535 V at current density of 10 mA∙cm−2. In contrast, the OER durability of these three samples was distinct. At 500 mV constant overpotential, the current density loss in OER of Ni/Ni-Fe NRAs was merely 13.5% for a period of 20000 s; but Ni/Ni-Mo and Ni/Ni-Co NRAs had almost disappeared catalytic activity under the identical conditions. According to many reports, the results were different for the superior OER stability of Ni-based bimetallic catalysts. Electrochemical analysis revealed that the NRAs structure dramatically improves charge transfer efficiency and electrochemically active surface area (ECSA). The present study might provide a new insight to design and fabricate more practical and high-performance Ni-based electrodes for OER.

Enhanced hydrogen production through alkaline electrolysis using laser-nanostructured nickel electrodes

This study describes the fabrication of ultrafast laser-induced periodic nanostructures on Nickel sheets and their use as cathodes in alkaline electrolysis. For the first time, to the best of our knowledge, laser-nanostructured Ni sheets were used as cathode electrodes in a custom-made electrolysis cell at actual, Hydrogen producing conditions, and their efficiency has been compared to the untreated Nickel sheets. The electrochemical evaluation showed higher Jpeaks, lower overpotential, and enhanced double-layer capacitance for the nanostructured electrode. A decrease in the Tafel slope was also found for the nanostructured electrode. The hydrogen production efficiency was found to be 3.7 times larger for the laser-nanostructured Nickel electrode, which was also confirmed by current-time measurements during electrolysis. Also, a novel approach is proposed to improve the stability of the current density during electrolysis and, therefore, the hydrogen production process by about 10%.

Carbon Dots Promote the Performance of Anodized Nickel Passivation Film on Ethanol Oxidation by Enhancing Oxidation of the Intermediate†

Main observation and conclusionEthanol is considered a better fuel than methanol in direct alcohol fuel cells because of the high energy density and low toxicity. Compared with noble metal catalysts, nickel‐based catalysts are much cheaper in price. However, present nickel‐based catalysts still surfer from some disadvantages such as low activity and high overpotential. In this paper, we show a new and high efficient nickel‐ based catalyst for ethanol oxidation. A layer of anodized nickel passivation film (Ni‐APF) was formed on the surface of nickel sheet by anodic oxidation method with carbon dots (CDs) as co‐catalyst. At the current density of 110 mA·cm−2, the potential for Ni‐APF/CDs was only 0.541 V (vs. Ag/AgCl), which was 18.8% lower than that of Ni‐APF. Low overpotential could reduce electrode thermal loss and increase output energy. Ni‐APF/CDs showed 144.4 mA∙cm−2 peak current density at peak potential 0.662 V (vs. Ag/AgCl), which was 31% higher than that of Ni‐APF (110.3 mA∙cm−2). In this system, CDs mainly function in the increase of charge‐transfer capacity and the promotion oxidation of carbonaceous intermediates.

Mechanical response of nickel multicrystals for shear and tensile conditions at room temperature and 573 K

The critical dimension (e.g. thickness for sheet, diameter for cylindrical part) of small components used in a miniaturized system is often a crucial factor affecting the mechanical behavior and the forming process, since in such length scale ranges the grain size is comparative to the mechanical part dimension. To have a better understanding of the mechanical behavior of microsized metallic parts, the size effects in 500 μm thick samples of nickel sheet were studied in tensile and shear loading states. The modifications of the mechanical behavior due to different numbers of grains across the thickness were thoroughly investigated at room temperature and 573 K. New experimental results obtained by shear tests at high temperature revealed that the transition from polycrystalline to multicrystalline behavior is more pronounced in tensile loading than in shearing conditions and that different surface sample state is observed. It was demonstrated that the reduced stress level effect depends not only on the temperature, but also on the stress state. In addition, with a moderate increase in temperature, the surface effects leading to the multicrystalline behaviors became more predominant in tensile condition than in shearing condition.

Perancangan Sensor LVDT dan Potensiometer Geser Sederhana Sebagai Alat Potensial Pendeteksi Pergeseran Tanah

A preliminary study on the design of a Linear Variable Differential Transformer (LVDT) sensor and a sliding potentiometer has been carried out. It is a distance measuring sensor that can be used as a ground shift sensor. This study aims to develop a new type of low cost mechanical sensor which has a high enough accuracy. The LVDT sensor is built using affordable materials such as PVC pipes, winding wires and iron cores, which is varied based on the number of primary coil and its diameter. While the potentiometer sensor is prepared by using linear bearing using electrode sheets of nickel and copper which is arranged by implemented the concept of the Newton-Wheatstone Bridge. The measurement value shows that the LVDT sensor with the number of primary coil of 110 and a diameter of 4 mm can measure with an accuracy of 0.5 mm and a range of more than 4 cm. While the sliding potentiometer using a sheet of copper electrodes can measure 0.5 mm with a range of more than 4 cm. The average error shown by the LVDT sensor and the sliding potentiometer is 5.2% and 6.4%, respectively.

Микроструктура и прочность соединений листов никеля, полученных ультразвуковой сваркой

Ultrasonic welding (USW) is one of the methods for producing solid-phase joints of thin metal sheets, which in the future can be used to obtain laminated composite materials, for additive manufacturing and renovation of metallic articles. The quality of joints depends on both the processing conditions and the properties of welded metals and alloys. At present, the USW conditions, the properties, and structure of weld joints of strong metals, in particular, of nickel, are underexplored. In this work, the authors studied the influence of the compressive load magnitude on the lap shear strength and the structure of joints of annealed nickel sheets with a thickness of 0.5 mm produced by spot USW. The authors carried out USW at a vibration frequency of 20 kHz with an amplitude of 15 μm, the time of welding was equal to 2 s. The compressive load magnitude was varied from 3.5 to 7 kN. The study showed that with an increase in the compressive load in the considered range of values, the strength of weld joints increased, reached a maximum, and then decreased. The joints obtained at the compressive load of 6 kN demonstrated the highest lap shear strength of 1950 N. A zone of thermomechanical influence with a gradient microstructure is observed near the contact of the welded surfaces. In a layer with a thickness of 10–20 mm, the initial coarse-grained structure of nickel is transformed into an ultra-fine-grained one with a grain size of less than 1 mm. The ultra-fine-grained layer neighbors on crystallites, the size of which is several micrometers and increases with a distance from the contact surface of welded sheets. The authors compared the results of mechanical lap shear tests and structural studies with the data obtained after ultrasonic welding of nickel, aluminum, and copper alloys.

Mechanically strong, thermally conductive and flexible graphene composite paper for exceptional electromagnetic interference shielding

In this work, a flexible yet strong graphene/nickel based composite paper (RGN paper) was fabricated by a one-step cold compression method at room temperature. The cellular structure of nickel foam provides a possibility for combining metal nickel and graphene sheets to construct sandwich-structured composite film with flexibility and robustness. The RGN paper not only shows exceptional EMI shielding effectiveness (55 and 85 dB in the X-band while the thickness is merely 0.12 or 0.25 mm), but also exhibits high in-plane thermal conductivity (247 W/(m·K), much higher than pure nickel). The ultrahigh EMI shielding performance is attributed to the high electrical conductivity of the RGN paper and the unique built-in nickel network. In addition, the RGN paper also indicates high flexibility and mechanical robustness after repeatedly bending at a strain of 80% for 1000 cycles.

In situ synthesis of NiO@Ni micro/nanostructures as supercapacitor electrodes based on femtosecond laser adjusted electrochemical anodization

Nickel oxide is a p–type transition metal oxide with excellent electrochemical performance, which is widely used in the application of supercapacitors. We introduce an approach of femtosecond laser ablation combined with electrochemical anodization for NiO nanostructures grow in situ on nickel sheet for supercapacitors electrodes. By controlling the processing conditions of femtosecond laser, various patterns covered the surface of nickel sheet, which promoted uniform NiO growth in situ on nickel sheet. Specific capacitance of the supercapacitor electrode fabricated using femtosecond laser pretreatment was superior to that of the NiO/Ni electrode prepared by electrochemical anodization alone at the current density of 1 mA cm−2. In addition, the capacitance retention of the NiO/Ni electrode for 1500 cycles was approximately 100%, and this electrode exhibited excellent conductivity according to electrochemical impedance spectroscopy measurements. According to these results, femtosecond laser enhanced electrochemical anodization was a promising approach for the fabrication of supercapacitors electrodes.

Microstructure and mechanical properties of copper to nickel ultrasonic spot welds

Ultrasonic spot welding has been used for joining copper and nickel sheets. With increasing the welding time, the lap shear tensile load of Cu/Ni joints first increases up to the maximum (1879.1 ± 39.3 N), and then decreases. The hardness of the Cu side along the weld interface increases due to enhanced plastic deformation and element diffusion at the Cu/Ni interface. The microjoints expand from the weld interface below the peak of the sonotrode tip to the weld interface below the valley of the sonotrode tip. The joining mechanism is element diffusion, the generation and progressive expanding of microjoints, and mechanical interlocking.

Interferometric Study of the Heat Transfer Phenomena Induced by Rapid Heating of Nickel Sheet

Visualization of the heat transfer phenomena induced by the rapid heating of nickel sheets was carried out using a Mach–Zehnder interferometer (MZI) and a high-speed camera. This phenomenon may be an important factor in heat transfer phenomena when the working fluids reach the thermodynamic critical point. The effect of heat transfer on the heating conditions of a nickel sheet was quantified by finite fringe analysis. The results show that isotherms near the heating surface with rapid heating are generated, and the induced isotherms are moved upward with similar patterns for different heating conditions. In addition, it is confirmed that the local Nusselt number decreases to the relationship of a secondary function if the thickness of the metal specimen is very thin and the time to reach the highest temperature is very short. Moreover, it decreased according to the increase of heating energy because the heat transfer mainly occurred by conduction and radiation rather than by convection, because the expansive force and compressive force between the fluid layers on the wall increased due to an increase in the heating energy in the beginning.

Three-Dimensional Binder Free Co-MOF@Co3O4/Ni Nanostructured Electrode for High Performance Supercapatteries

Inflating energy consumption of modern society demands sustainable energy storage device. Optimization of energy along with power density is the major concern for a sustainable energy storage device. Different types of materials are used for both supercapacitors and batteries. Usually carbon based materials are used as electric double layer capacitor (EDLC) and transition metal oxide and conducting polymers are used as pseudocapacitive type materials[1]. Transition metal oxides like Co3O4 [2] , NiCo2O4 [3]and Bi2O3[4] etc. are used as battery type materials. Hybridization of both battery and supercapacitor type materials can give high specific capacitance as well as high specific surface area and conductivity thus maximizing both energy density and power density of the electrode material. Metal organic frameworks (MOFs) are consisting of covalent bonds between transition metal ions and organic linkers containing carboxylic groups or imidazole groups[5]. These novel materials can provide very high specific surface area, good tailorability, and appreciable aspect ratio etc. A number of literature on MOF based energy storage device material are fabricated by binder method [6]. Use of binder lessens the conductivity and the active surface area of the electrode material. If a transition metal oxide is formed directly on a conducting substrate and over that, a MOF is formed then the morphology of the entire electrode will not only provide three-dimensional nanostructure but also high surface area, porosity and appreciable aspect ratio. Therefore, this approach can be proved as a highly fruitful for the synthesis of an excellent supercapattery device.In this work, an approach to synthesize a three-dimensional binder-free electrode material based on cobalt-metal organic frameworks (Co-MOF) grown over cobalt oxide is adopted. Cobalt oxide is grown over nickel sheet (Co3O4/Ni) via hydrothermal process followed by solvothermal process for the formation of Co-MOF@Co3O4/Ni using trimesic acid as organic linker. The structural, morphological and compositional confirmation was accomplished through X-ray diffraction (XRD) analysis, Field emission scanning electron microscopy (FE-SEM) and X-ray photoelectron spectroscopy (XPS) analysis, respectively. The image delivers a three-dimensional micro-flower structure embedded with multidimensional polygons with good porosity and high specific surface area (Fig. 1). Herein the cobalt oxide forms a three-dimensional micro flower structure and the growth of MOF over that adds extra porosity, surface area and stability. The electrochemical characterization was accomplished through cyclic voltammetry (CV), galvanostatic charge/discharge (GCD) and electrochemical impedance spectroscopy (EIS) analysis using a three electrode system in 1M KOH solution. The Co-MOF@Co3O4/Ni binder-free electrode showed a battery type behavior i.e. redox peaks in both CV and GCD curve. The specific capacity obtained from cyclic voltammetry analysis was 539 mC/cm2 at scan rate of 5mV/s. This binder free and three-dimensional porous architecture electrode avoids the use of extra additive and provide large specific surface area and porosity for the easy access of electrolyte ions and charge storage and better electrical conductivity for the fast electron transportations. Hence, this novel three-dimensional binder-free Co-MOF@Co3O4/Ni electrode can be proved as an excellent candidate for supercapattery device.The detailed experimental results and discussion will be presented in the meeting. Acknowledgements: This research work is financially assisted by the Department of Science and Technology-Inspire (DST-Inspire) Fellowship (IF170869), by Govt. of India.

Notch impact toughness of laser beam welded thick sheets of cryogenic nickel alloyed steel X8Ni9

The paper deals with the investigations of the impact toughness of laser beam welded 14.5 mm thick sheets made of cryogenic steel X8Ni9 as a function of preheating. This 9% nickel alloyed steel is widely used in the liquefied natural gas (LNG) industry. An application of highly efficient welding processes such as high-power laser beam welding (LBW) in LNG sector requires an understanding of the interactions between the LBW process parameters and weld properties, in particular the impact toughness. The results show that the original fine-grained martensitic microstructure of the base metal (BM) is significantly changed by melting and crystallization during the LBW, what can lead to a decrease in the impact toughness of the weld metal (WM) below the required level. An optimal preheating temperature range leads to the favorable thermal welding cycle and is of remarkable importance for maintaining the notch impact toughness of laser beam welded joints of these thick steel sheets. A parameter window was identified in which V-notch impact toughness comparable to that of the BM at -196 °C was achieved.

Hydrogen ion beam transport in an energy range lower than 50 eV: Ion beam species.

Low energy beam transport in the energy range below 50 eV is studied using a compact ion source with a high temperature tungsten cathode that can be put into a vacuum system. A 2.6 cm diameter, 5.2 cm long compact ion source successfully produced more than 2.4 nA beam of H2 + ions at 50 eV beam energy. The source also supplied a stable beam of H3 + ions at 2.5 eV energy with more than 100 pA mass-separated current. The inside wall of the ion source was covered by thin sheets of titanium, nickel, and molybdenum to see if the species composition of the ion beam can be controlled by changing the ion source wall material. Usually, the H2 + ion peak was the highest in the mass spectrum, and the H2 + ion ratio (H2 +/Hn +) was measured for a source operation with hydrogen gas. The ion species ratio drifted against time, and Mo showed the most stable ion ratio.

EDM of Nickle and Titanium Alloy Sheets aided by Vibration

Nickel and titanium alloys are widely used as aero-engine blade materials due to their excellent properties such as high strength, light weight and resistance to high temperature. There are many methods available to machine materials to the required dimensions and with high blade accuracy. Electrical chemical machining (ECM) is one of them. However, the complexity of flow field and electric field on the leading and trailing edges of the blade during ECM results in large dimensional and shape errors. The edges must be dressed to the required dimensions and accuracy. Electric discharge machining (EDM) has the ability to remove any electrically conductive material regardless of its strength and hardness. In this paper, EDM aided by vibration is used to roughly dress the leading and trailing edges of the blade. To optimize machining parameters such as peak current, pulse on-time, amplitude and frequency of vibration, extensive experiments are carried out based on orthogonal method. Thin sheets of nickel and titanium alloys with cross section of 29 mm × 0.5 mm are cut off 2mm in length. The optimal machining parameters were verified by confirmation experiments. It was found that under optimal conditions and using graphite electrode, machining time of nickel alloy was 1.62 minutes and machining time of titanium alloy was 2.12 minutes. The corresponding electrode wear ratio and heat affected zone were analysed.

Grain Orientation Induced Softening in Electrodeposited Gradient Nanostructured Nickel during Cold Rolling Deformation

AbstractQuantitative microstructural evolution and the corresponding microhardness of electrodeposited nanostructured nickel sheet during cold rolling deformation are investigated by x-ray diffraction, transmission electron microscopy and Vicker’s microhardness testing. Particularly, to investigate the effect of stress states on deformation behavior, two series of gradient nanostructured nickel with symmetric structures and the homogeneous counterparts with three levels of grain size are compared based on macro-statistical data. In such hierarchical sandwich-like gradient samples, the layers with larger grain size, as the soft phase, indeed sustain more deformation. Deformation-induced grain rotation changes are observed in the center layers with a relatively larger grain size, accompanied by an obvious decrease in microhardness. According to the quantitative microstructural parameters including the grain size, dislocation density and stacking fault probability before and after deformation, evaluation based on Hall-Petch and Bailey-Hirsch relationships indicates the transition from strain hardening to softening can be attributed to grain orientation change.

Recovery of Ni(II) from real electroplating wastewater using fixed-bed resin adsorption and subsequent electrodeposition

Effective recovery of high-value heavy metals from electroplating wastewater is of great significance, but recovering nickel ions from real electroplating wastewater as nickel sheet has not been reported. In this study, the pilot-scale fixed-bed resin adsorption was conducted to recover Ni(II) ions from real nickel plating wastewater, and then the concentrated Ni(II) ions in the regenerated solution were reduced to nickel sheet via electrodeposition. A commercial cation-exchange resin was selected and the optimal resin adsorption and regeneration conditions were investigated. The resin exhibited an adsorption capacity of 63 mg/g for Ni(II) ions, and the average amount of treated water was 84.6 bed volumes (BV) in the pilot-scale experiments. After the adsorption by two ion-exchange resin columns in series and one chelating resin column, the concentrations of Ni(II) in the treated wastewater were below 0.1 mg/L. After the regeneration of the spent resin using 3 BVof 4% (w/w) HCl solution, 1.5 BV of concentrated neutral nickel solution (>30 g/L) was obtained and used in the subsequent electrodeposition process. Using the aeration method, alkali and water required in resin activation process were greatly reduced to 2 BV and 3 BV, respectively. Under the optimal electrodeposition conditions, 95.6% of Ni(II) in desorption eluent could be recovered as the elemental nickel on the cathode. The total treatment cost for the resin adsorption and regeneration as well as the electrodeposition was calculated.