Wire Explosion Research Articles

Metal, Metal Composite, and Composited Nanoparticles Obtained by Electrical Explosion of Wires

Nanoparticles (NPs) possess a unique combination of physicochemical properties, which makes them promising materials for use in such fields of science and technology as materials science, biomedicine, and catalysis. This review presents data on the structural characteristics of metal, alloy, and composite NPs, as well as metals oxide, carbide, and nitride NPs, obtained by electrical explosion of wires (EEW). The main attention is paid to the relationship of the size distribution and phase composition of NPs with the EEW conditions and the parameters of the buffer medium (chemical composition, pressure) in which the explosion is performed. The analysis of the studies show that EEW makes it possible to obtain a wide range of NP-based powders.

Discharge characteristics and spatial-temporal evolution of Cu-Ni alloy wire explosion

Electrical explosion of wires (EEW) driven by pulse current can produce plasmas with high energy density, and is accompanied by electromagnetic pulses, strong shock waves, etc., therefore it is widely adopted in Z-pinch, electrothermal chemical weapons, oil and gas exploitation and other fields. Compared to pure metal, alloy has characteristics of the high resistivity, adjustable composition, and complex phase transitions. It has great potential in regulating parameters of EEW. This paper presents an experimental study on exploding Cu, Ni, and Cu-Ni alloy (constantan) wires in atmospheric air under a microsecond time-scale pulsed current. Through the diagnoses of electrical parameters and self-emission images, the discharge characteristics and spatial-temporal evolution of explosion products were obtained. Features of the alloy wire explosion in phase transition and plasma were acquired as well. Experiments revealed that in the early stage of EEW, the high resistivity of the alloy could improve the energy deposition efficiency, namely 52% for Cu, 74% for Ni, and 78% for Cu-Ni, while after the explosion, performance of the alloy wire was closer to that of the Ni wire. The initial expansion rate of the plasma channel reached 5 mm/μs level but then decayed. The expansion process of alloy wire endured longer, and the average resistivity went up slowly after the breakdown. Also, a correlation was found between plasma radiation and metal aerosol in spatial scale. Especially, the alloy aerosol has crossed striation features (10−1 mm), but it is more uniform than Cu aerosol generally.

Underwater electrical wire explosions can destroy steel plate

By using pulsed power to explode underwater wire arrays, researchers create dense water jets with extremely high energies and velocities.

Role of wire diameter size in the high voltage pulse wire explosion: Insights from molecular dynamics simulations

We performed molecular dynamics simulations of the high voltage pulse explosion of single aluminum wires with the energy ratio of 0.6 in vacuum and studied the role of wire radial dimension. Simulation results show that large-diameter wires having a large material depth and a small specific surface can maintain a higher deposition energy density and effectively reduce the influence of the radial difference in thermodynamic parameters, leading to higher explosion velocity and a lower vaporization rate in the large-diameter wire. The most significant effect is that the larger diameter wire has a longer explosion development time. In addition, the propagation and reflection of the rarefaction waves in the wire result in two explosion regimes: the spinodal decomposition propagating inward from the surface and the cavitation boiling from the center to the surface. Increasing the diameter will increase the domination range of the spinodal decomposition mechanism.

Spectroscopic quantification of the nanoparticle production efficiency of copper wire explosion

Wire explosion is a technically straightforward green method for nanoparticle production; however, the determination of polydisperse and multimodal particle size distribution and thereby the assessment of the efficiency of the process pose serious challenges. Fitting extinction spectra derived from the Mie theory to the measured extinction spectra of colloidal solutions produced by the explosion of copper wires of 70 μm diameter and 20 mm length by discharging a capacitor of 435 nF charged to voltages ranging from 4 to 12 kV in an aqueous environment allows for determining the size distribution of the particles in the 10–300 nm diameter range and provides information on their oxidation state as well. In underwater wire explosion of copper, the vast majority of the nanoparticles transforms into copper oxides already during the process. The size distribution remains bimodal throughout the whole charging voltage range investigated. The nanoparticles follow a lognormal size distribution with a mode at 30 nm, while the fine particle population extending from 100 to 300 nm in diameter is dominated by rather normally distributed copper droplets with modes at 160–170 nm. The energy injected into the wire controls the individual concentration of both the fine and nanoparticles with the modes and ranges remaining hardly affected. The number concentration of the nanoparticles increases monotonically with the energy, spanning more than one order of magnitude. The throughput assessed by the total mass of the nanoparticles divided by the total mass of all species identified in the sol within the 0–300 nm diameter range increases monotonically from 1% at 4 kV up to 41% at 12 kV, revealing that wire explosion can be optimized for efficient nanoparticle production.

Effect of synthesis conditions on the morphology, composition and magnetic properties of the iron oxide nanoparticles prepared via electric discharge method

In this study, iron oxide nanoparticles (IONPs) were synthesized via explosion of ST37 wires with various diameters in distilled water. Synthesized IONPs were studied by XRD, UV_ visible, FE_SEM, EDS and VSM analyzes. The XRD results showed that the produced powders are magnetite (Fe3O4) with cubic structure. The UV–visible results confirmed the results of the XRD and the presence of magnetite by showing the peak in the 200 nm range. FE_SEM results revealed that synthesized IONPs were spherical in shape. According to XRD and FE_SEM results, with increasing in the wire diameter, the size of nanoparticles was increased and as a result, the saturation magnetization was also increased.

Single step synthesis of WO3 nanoparticles by wire explosion process and its photocatalytic behaviour

Tungsten (W) wires are exploded in oxygen ambience to get tungsten oxide (WO3) nanoparticles (NPs). Energy stored in the capacitors (EC) is used to overcome the sublimation energy of wire. Energy ratio (K, ratio of EC and sublimation energy) and oxygen pressure (P) are two control parameters for the particle phase and morphology in the wire explosion process. X-ray diffraction (XRD) patterns confirmed the partial oxidation of W for low values of K. For K = 2, oxidation increases with increase in P. For K = 10, complete oxidation was achieved irrespective of P. Particles are spherical in shape as observed from scanning electron microscope (SEM) and transmission electron microscope (TEM) micrographs. Particle size follows a log-normal distribution with a least mean size of 24.1 nm. UV-vis diffuse reflectance spectroscopy (DRS) was used to measure the absorbance of NPs (complete WO3 with least mean size) for band gap measurement. The band gap was found to be 2.92 eV (visible region). NPs are used as photocatalyst to degrade aqueous solution of methylene blue (MB) under visible light irradiation. 500 mg l−1 of WO3 NPs were optimum to degrade 10 mg l−1 MB in 120 min.

Electrophoretic deposition of coatings and bulk compacts using magnesium-doped aluminum oxide nanopowders

The electrophoretic deposition (EPD) of coatings and bulk compacts in a wide range of thicknesses (from 23 to 1800 μm) from stable suspensions of a magnesium-doped aluminum oxide nanopowder with subsequent sintering of samples into dense ceramics was studied. The initial nanopowder was obtained by the method of electric explosion of an Al-Mg alloy wire with a Mg content of 1.3 wt. %. The study of the dispersion composition, kinetics of deaggregation under the ultrasonic treatment and zeta potential in the nanopowder-based suspensions was carried out. It was shown that a nearly linear increase in the deposited mass and thickness of EPD deposits occurred at a constant voltage of 20 V and an average deposition current of approximately 40 μA when the deposition time was varied from 1 to 180 min. Drying of the coatings with a thickness of less than 35 μm led to the formation of a net of small cracks, while drying of the bulk compacts with a thickness of more than 1 mm occurred without cracking. The ceramic bulk sample with a thickness of 1.2 mm and the density of 98.7% TD was successfully obtained by sintering at 1650 °C for 4 h. It was characterized by a dense grain structure with an average grain size of 5 μm and the presence of a small number of closed pores less than 1 μm in size. Sintering of ceramics was revealed to be accompanied by the formation of a MgAl2O4 crystalline spinel phase, localized mainly at grain boundaries.

One-step synthesis of FeO(OH) nanoparticles by electric explosion of iron wire underwater

In this study, we investigated electric explosion of iron wire in distilled water with different energy input adjusted by charging voltage. The as-prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS), showing the presence of iron and multiple iron-based compounds oxides with contents influenced by the experimental conditions. In particular, pure FeO(OH) nanoparticles were obtained using electric explosion of iron wire with energy input of 1125 J at charging voltage of 15 kV. Analysis of discharge current and resistive voltage data indicate that the high energy input induced by strong plasma discharge at high charging voltage is a key factor to form FeO(OH). This study presents a one-step method to synthesize FeO(OH) nanoparticles using electric explosion of iron wire.

Electrical Explosion Synthesis, Oxidation and Sintering Behavior of Ti-Al Intermetallide Powders

In this research, Ti-Al powders were produced by electrical explosion of twisted titanium and aluminum wires. The resulting powders were pressed and sintered in a vacuum to obtain bulk composites. Transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), scanning electron microscopy (SEM), and X-ray diffraction (XRD) studies were performed to analyze synthesized powders and bulk composites. The studies carried out showed the presence of α-Ti, α2-Ti3Al, and γ-TiAl phases, which are formed by coalescence of Ti and Al clusters formed in the process of non-synchronous electrical explosion of twisted wires. Furthermore, an increase in the energy injected into the wires leads to a decrease in the content of micron particles in the powder. During sintering of pressed Ti-Al powder in the range 800–1250 °C, phase transformations occur due to the diffusion of aluminum atoms towards Ti compounds. The research findings can be used to obtain Ti-Al particles and bulk composites with a controllable phase composition.

Influence of Structure and Dispersivity of Copper on its Melting Features

The melting parameters (melting point, specific heat of fusion) of copper samples with different volume structure (fine-grained, submicrocrystalline) and dispersivity (fine powder) were explored using differential thermal analysis. It was found that change in the metal structure from bulk coarse-grained to submicrocrystalline, and to submicron powders led to depression of melting point by ~18 °C and of specific heat of fusion by ~45 % relative to the standard values. It was shown that the high-energy impact on the starting coarse-grained metal used to obtain the samples with modified structure and dispersivity (severe plastic deformation, electric explosion of thin wires) caused changes in the composition of the material. An explanation for the observed influence of structure and dispersion factors on the melting parameters has been proposed on the basis of X-ray diffraction data, electron microscopy, and model calculations.

Features of Structural-Phase Transformations during Oxidation of Metals with Bulk Submicrocrystalline Structure and Fine Metal Powders

The oxidation processes for compact and powdery samples of titanium, copper, and molybdenum with different volume structure and dispersivity were studied using thermal analysis, electron microscopy, and X-ray diffraction. It is established that producing of metals with a modified structure under conditions of high-energy impact (severe plastic deformation, electric explosion of a thin wire) in accordance with intermediate annealing leads to an increase in the content of oxygen in the form of solid solutions and oxides; the oxide component’s share, form and localization within the material depend on physicochemical properties of both metal and oxide . It is shown that the structural-phase transformations of the oxide component during heating of fine-grained metals and powders have a significant effect on the parameters of the oxidation process of such materials. The thermally induced effects in the oxygen-containing components might play a critical role for the structure stability during long-term use of such materials under cyclic thermomechanical impacts.

A novel method of processing sheet metals: Electric-pulse triggered energetic materials forming

• A novel high-velocity sheet metal forming method is proposed: ETEF. The energetic materials (EMs) were introduced into the EHF system, and the electrical explosion of metal wire ignited EMs and released energy. • The EMs under the 10 wt.%Al/90 wt.%AP conditions exhibited the highest energy release efficiency, the energy grade of EMs was determined to be 3.04 kJ/g in this work. Under discharge voltage of 3 kV, the bulging height of DP600 specimen from ETEF was increased by 162 % relative to that from EHF. • Compared with that of EHF/7 kV, the strain concentration area of the sheet under the ETEF was wider (about 60 mm). The maximum major strain and maximum thinning rate of the specimen under the 2 g/3 kV/10 wt.% Al/90 wt.% AP conditions were reduced by 10.6 % and 13.1 %, respectively. • The dynamic deformation of the DP600 specimens during ETEF were presented for the first time by LS-DYNA. The EMs were ignited by electric explosion of metal wire to realize the coupling of two kinds of energy. To improve the formability of sheet metals at room temperature and overcome the limitation of the upper limit of energy storage in electrohydraulic forming (EHF), a novel sheet metal forming is proposed: electric-pulse triggered energetic materials forming (ETEF). The power to deform a metal sheet originates from the electrical explosion of a metal wire in a liquid chamber and that releasing chemical energy from the energetic materials (EMs) being triggered. Equi-biaxial stretching tests of DP600 were carried out through ETEF with different weight ratios and changing grams under a low discharge voltage. The final profiles, strain and thickness distribution of the sheet were analyzed. The energetic materials with 10 wt.%Al/90 wt.%AP had an energy level of 3.04 kJ/g, and the bulging height of the deformed specimen was 34 mm, which was higher than the energy levels obtained under other testing conditions. Compared with that of the 7 kV specimen of the same bulging height (34 mm) obtained by EHF, the strain concentration region of the specimen processed under the 2 g/3 kV/10 wt.% Al/90 wt.%AP conditions widened by 52.5 %, and the maximum major strain and maximum thinning rates were lower by 10.6 % and 13.1 %, respectively. The dynamic deformation characteristics of the DP600 specimens during ETEF were presented for the first time by LS-DYNA. The values obtained for the DP600 sheet were as follows: maximum bulging height, 32 mm; maximum effective strain rate, 1521/s; and maximum speed, 258 m/s.

The Effect of Plasmonic Nanostructures Prepared by Electrical Exploding Wire Technique on the Optical Properties of R6G Dye

The Effect of Plasmonic Nanostructures Prepared by Electrical Exploding Wire Technique on the Optical Properties of R6G Dye

Anomalous magnetic behavior in Ni80Cr20 nanoparticles prepared by physical and chemical methods

We report a detailed study of the structural and magnetic properties of Ni80Cr20 fine particles prepared by physical methods, such as mechanical alloying, wire explosion process (WEP), and chemical methods like sodium borohydride reduction, polyol method. From the analysis of structural and microstructural data, phase formation with the desired composition is confirmed in the particles prepared by the WEP. A comparative study of magnetization data of bulk and nanoparticles of Ni80Cr20 suggests that a weak magnetic moment develops in nanoparticles due to finite-size effects. Analysis of magnetization data suggests a superparamagnetic (SPM) behavior in the smallest sized (34 nm) particles prepared by WEP, while nanoparticles prepared by other methods show ferromagnetic ground state. Further, it is shown that the origin of weak magnetic moment and development of SPM state in the nanoparticles is due to uncompensated surface spins with a negligible interaction effect.

Numerical Simulation on the Formation and Pinching Plasma in X-pinch Wires on 2-D Geometry

This paper deals with the computational work to characterize the formation and pinching of a plasma in an X-pinch configuration. A resistive magnetohydrodynamic model of a single fluid and two temperature is adopted assuming a hollow conical structure in the (r,z) domain. The model includes the thermodynamic parameter of tungsten from the corrected Thomas-Fermi EOS(equation of state), determining the average ionization charge, pressure, and internal energy. The transport coefficients, resistivity and thermal conductivity, are obtained by the corrected Lee & More model and a simple radiation loss rate by recombination process is considered in the simulation. The simulation demonstrated the formation of a core-corona plasma and intense compression process near the central region which agrees with the experimental observation in the X-pinch device at Seoul National University. In addition, it confirmed the increase in radiation loss rate with the density and temperature of the core plasma. Keywords: X-pinch, Magnetohydrodynamics, Exploding Wires Keywords: 엑스핀치, ìžê¸°ìœ ì²´ì—­í•™, ì„¸ì„ í­ë°œ

Electric explosion of wires as versatile method for antibacterial Janus-like ZnO–Ag nanoparticles preparation

Electric explosion of zinc and silver intertwined wires in an oxygen-containing atmosphere was used for the first time to produce ZnO–Ag bicomponent nanoparticles. Silver content was regulated by wire diameters. The nanoparticles were characterized by transmission electron spectroscopy, X-Ray diffraction. Optical properties of ZnO–Ag nanoparticles were studied by ultraviolet–visible spectroscopy. The phase state of nanoparticles in the range of high (12–35%) silver content has been established, which provides an increase in the photocatalytic activity in the visible spectral range. The Methylene blue degradation efficiency by ZnO-12Ag nanoparticles reached 90%, which was higher than that of ZnO nanoparticles produced by electric explosion of zinc wire. Composites had high antibacterial activity against Escherichia coli bacteria.

Synthesis of Fe/Fe3O4 core-shell nanoparticles by electrical explosion of the iron wire in an oxygen-containing atmosphere

Magnetic nanoparticles based on iron and its oxides are promising in various biomedical applications. Currently, as a rule, ferromagnetic iron oxide particles with a low specific magnetic moment are used for medical purposes. In the present work, a new method for the synthesis of magnetic nanoparticles based on the electric explosion of a Fe wire is proposed. When wires are dispersed by high current electric pulse in an inert atmosphere containing less than 5% oxygen, nanoparticles with a core-shell structure are formed, where the core is α-Fe and the shell is formed by a mixture of oxides Fe3O4 and FeO. The oxygen concentration in the buffer gas has been found to determine the size of the resulting nanoparticles, their shape, and iron content. The iron oxide shell protects the iron core from the external environment, preventing the rapid dissolution of Fe containing in the nanoparticles, in contrast to nanoparticles obtained in argon atmosphere. The specific magnetic moment of nanoparticles, depending on the content of iron oxides, varies from 90 to 180 emu/g.

Free‐standing molybdenum disulfides on porous carbon cloth for lithium‐ion battery anodes

In this study, a free-standing MoS2 nanofilm on a porous carbon cloth (MoS2@PCC) was prepared for application as an anode in Li-ion batteries. Uniform, non-aggregated MoS2@PCC electrodes were synthesized via facile electric-wire-explosion, dip-coating, and thermal sulfidation processes. The phase and morphologies were controlled using a variety of explosion media that had different carbon contents. The dip-coating of PCC into a colloidal solution prepared by underwater explosion of Mo metallic wire and the thermal sulfidation process provided higher uniformity of MoS2 nanoparticles with no particle aggregation. This facilitated the charge transfer and accommodation of volume expansion of Li-active MoS2 upon cycling. Consequently, the free-standing MoS2@PCC electrodes exhibited enhanced lithium reactivity, high rate capability, and cycle durability, compared with the conventional MoS2 nanoparticle electrode.

Laser scattering by submicron droplets formed during the electrical explosion of thin metal wires

This paper presents the results of studying dispersed media formation during the electrical explosion of thin metal wires in vacuum by using low-current generators (∼1–10 kA). Particular attention is paid to the analysis of the composition and structure of the corresponding explosion products as well as to the problem of their visualization using simultaneous laser interferometry and shadow imaging at two wavelengths (1.064 µm and 0.532 µm). Our findings indicate the important role in the visualization of the explosion products that belongs to multiple scattering by submicron droplets of dense condensed matter, which are mixed with metal vapor. The hypothesis on the existence of submicron droplets in the products of exploding metal wires correlates with the results obtained by soft x-ray radiography combined with a laser probing technique. Taking into account the multiple scattering by submicron droplets, it is possible to significantly clarify the parameters of the explosion products visualized via laser probing techniques as well as to gain a deeper insight into the physics behind the electrical wire explosion.