Electrical Wire Explosion Process Research Articles

Research on the sub-millisecond underwater electrical wire explosion process

Abstract Underwater electric wire explosion (UEWE) has great potential as a shockwave source for medical and industrial applications. This paper focuses on the process of the sub-millisecond underwater electrical wire explosion (smUEWE). The study compared the smUEWE and the microsecond underwater electrical wire explosion, which revealed the occurrence of partial vaporization under smUEWE, leading to the formation of bamboo-shaped cavities and frontal shock waves. The experiments of smUEWE were carried out under different stored energy, the results indicated the plasma shrinkage and cavity separation during the overall ionization process. Additionally, the study observed secondary breakdown caused by the uneven distribution of ionization products. An analysis was conducted on smUEWE considering partial vaporization, which divided the electrical explosion into a positive feedback process which promoted the axial instability and a negative feedback process which formed the uniform plasma channel. The analysis results was consistent with the experimental results.

Synthesis and characterization of hypoeutectic Al-Mg nano powder produced by electrical explosion method

Hypoeutectic composition of Al-Mg alloy binary system was established as a stabilized composition for production of Al-Mg alloy nano powders for fabrication of solid propellant. Nano powder of hypoeutectic Al-Mg alloy was prepared by high voltage Electrical Wire Explosion Process (EEW) under inert Argon and Helium gas environment with chamber pressure of 25 kPa and 50 kPa. The thin wires for explosion were prepared by Electrical Discharge Machining (EDM) process from Al-Mg alloy cast. XRD analysis of powder produced and alloy cast was performed to compare the phases present. Scanning Electron Microscope (SEM) images were taken for studying the shape and structure of the nano powder particles and Energy Dispersive Analysis of x-rays (EDX) was performed for affirming elemental composition of alloy powder. Morphological characteristics of nano powders were analyzed by Transmission Electron Microscope (TEM) images and the particle diameter was found ranging from10 nm to 90 nm. Highly magnified TEM images were obtained to analyze the formation of various phases in the powder. Thermo-Gravimetric Analysis and Differential Scanning Calorimetry (TGA-DSC) measurements were made to substantiate the low melting nature of Al-Mg alloys predicted by Al-Mg binary phase diagram with an offset temperature of melting 460 °C, which is much closer to the eutectic melting point (450 °C) of Al-Mg binary metal alloy. With the improved ductility of hypoeutectic alloys enabling better machinability to produce thin wires than eutectic composition, the results suggests hypoeutectic nano powders can be used as replacement for nano aluminium as energetic element in solid propellants.

Combustion mechanism of composite solid propellant sandwiches containing nano-aluminium

Combustion of sandwiches made of alternating laminae of ammonium perchlorate (AP) and a matrix of hydrocarbon binder mixed with fine AP and nano-aluminium particles is considered in the 1–12MPa pressure range. Companion non-aluminized sandwiches are studied for comparison. The nano-Al particles are produced from the electrical wire explosion process in the size range ∼45nm, and added to the matrix containing either 5 or 45µm AP particles. Three categories of middle lamina thicknesses—thin (100–170µm), intermediate (200–280µm), and thick (370–480µm)—are examined in all the sandwiches. High-speed high-magnification imaging of the combustion is performed, and surface profiles and features of quenched sandwiches are investigated, besides burning rate measurements. The sandwich burning rates are compared with those of the corresponding matrices and AP laminae burning alone as well. The results imply the close location of lamina leading edge flames (L-LEFs) over the lamina interface edges, leaving the outer AP laminae inclined steeply relative to the matrix middle lamina, in the nano-aluminized cases relative to the non-aluminized versions. This observation suggests that the L-LEFs control the burning rates of the sandwiches even in the case of the fast burning matrix that contains nano-Al. The non-aluminized sandwiches containing the 5µm AP show higher burning rates than their 45µm AP counterparts because of the enhanced heat feedback available to the matrix burning surface from the extended fuel-rich branches of adjacent L-LEFs in the former case. Therefore, the enhancement in burning rate is minimal with the inclusion of nano-Al in sandwiches with smaller fine AP size, whereas the nano-aluminized sandwiches containing larger fine AP particles exhibit such enhancement. These effects affirm previous results on propellants with smaller fine and coarse AP sizes, where the burning rate is not enhanced by nano-Al.

Thermodynamic modeling and characterizations of Al nanoparticles produced by electrical wire explosion process – CORRIGENDUM

Thermodynamic modeling and characterizations of Al nanoparticles produced by electrical wire explosion process – CORRIGENDUM

Thermodynamic modeling and characterizations of Al nanoparticles produced by electrical wire explosion process

Abstract

Characterization of Magnesium Oxide Nanosheets Prepared by Electrical Wire Explosion Process

Characterization of Magnesium Oxide Nanosheets Prepared by Electrical Wire Explosion Process

Rapid fabrication and characterization of spherical Mumetal nanoparticles by an electrical wire explosion process

abstractSpherical Mumetal nanoparticles fabricated by the electrical wire explosion process in 1% solution of poly(acrylamide-co-acrylic acid) partial sodium salt as the explosion medium and capping agent to prevent particle agglomeration and control the size of nanoparticles. The structure, morphological features were studied by field-emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDX) and Transmission Electron Microscope (TEM). The size distribution and the principle elements analysis of Mumetal nanoparticles were analyzed. The DC magnetic properties of Mumetal nanoparticles were carried out on a Quantum Design superconducting quantum interference device (SQUID) and the temperature-dependence of mass magnetic susceptibility χ (T) and its inverse 1/χ for the Mumetal nanoparticles were measured in field-cooling (FC) procedures in an applied magnetic field of 50000 Oe between 2 and 300 K.

Electrical wire explosion process of copper/silver hybrid nano-particle ink and its sintering via flash white light to achieve high electrical conductivity

In this work, combined silver/copper nanoparticles were fabricated by the electrical explosion of a metal wire. In this method, a high electrical current passes through the metal wire with a high voltage. Consequently, the metal wire evaporates and metal nanoparticles are formed. The diameters of the silver and copper nanoparticles were controlled by changing the voltage conditions. The fabricated silver and copper nano-inks were printed on a flexible polyimide (PI) substrate and sintered at room temperature via a flash light process, using a xenon lamp and varying the light energy. The microstructures of the sintered silver and copper films were observed using a scanning electron microscope (SEM) and a transmission electron microscope (TEM). To investigate the crystal phases of the flash-light-sintered silver and copper films, x-ray diffraction (XRD) was performed. The absorption wavelengths of the silver and copper nano-inks were measured using ultraviolet–visible spectroscopy (UV–vis). Furthermore, the resistivity of the sintered silver and copper films was measured using the four-point probe method and an alpha step. As a result, the fabricated Cu/Ag film shows a high electrical conductivity (4.06 μΩcm), which is comparable to the resistivity of bulk copper (1.68 μΩcm). In addition, the fabricated Cu/Ag nanoparticle film shows superior oxidation stability compared to the Cu nanoparticle film.

Preparation of conductive metal patterns using Cu nano-colloids prepared by electrical wire explosion process

A simple patterning process to prepare conducting circuits in the atmosphere with the irradiation of laser and complex Cu nano-colloid was demonstrated. Stable Cu nano-colloids with a particle size of less than 10 nm were produced by an electrical wire explosion process in anhydrous ethanol. Uniform Cu film without cracks was prepared by using a Cu nano-colloid with copper(II) nitrate trihydrate. Various kinds of conductive Cu patterns on a flexible substrate were prepared by laser irradiation in air. The Cu pattern on a flexible polyimide substrate showed about 40 Ω/square of electrical sheet resistance.

Highly Reversible Li Storage in Hybrid NiO/Ni/Graphene Nanocomposites Prepared by an Electrical Wire Explosion Process

NiO/Ni/graphene nanocomposites were prepared using a simple and environmentally friendly method comprising an electrical wire pulse technique in oleic acid containing graphenes and subsequent annealing to form anodes for Li ion batteries. The control product of NiO/Ni nanocomposite was prepared under the same conditions and characterized by structural and electrochemical analysis. The obtained NiO/Ni/graphene nanocomposite particles had sizes of 5-12 nm and a high surface area of 137 m(2) g(-1). In comparison to NiO/Ni, NiO/Ni/graphene exhibited improved cycling performance and good rate capability. Reversible capacity was maintained at over 600 mA h g(-1) at 0.2 C and was attributed to the alleviation in volume change and improved electrical conductivity of NiO/Ni/graphene nanocomposites.

Preparation of Conductive Cu Thin Film by the Reaction of Cu Nitrate with Polymers

Cu nanoparticle-colloid was prepared by using electrical wire explosion process in liquid and it showed good dispersion stability without any kinds of additives. Mixed Cu nano-colloid was prepared with Cu nanoparticle-colloid, Copper (II) nitrate trihydrate, and polyvinyl pyrrolidone. Cu atoms are supplied from the dissociation reaction between Copper (II) nitrate trihydrate and polyvinyl pyrrolidone and fill up the gaps between Cu nanoparticles during the thermal sintering. Conductive (45 microOmega cm) Cu film was prepared at the sintering temperature of 200 degrees C by the enhancement of the formation of sintering necks.

Large-Scale Synthesis and CO Oxidation Study of FeCr Alloy Supported Pt Nanocatalyst by Electrical Wire Explosion Process

Platinum nanoparticles supported on FeCr alloy have been synthesized at a large-scale by sequential electrical explosion of FeCr alloy and Pt wires in ethanol. X-ray diffraction showed corresponding peaks of non-oxide phase Pt and FeCr alloy nanoparticles. Transmission electron microscopy showed uniform dispersion of Pt nanoparticles on the support with an average size of 2 nm and high thermal stability up to 600 °C. These Pt-FeCr alloy nanoparticles were found to be active for CO oxidation with an activation energy of 15 kcal mol−1 and negligible deactivation. This work demonstrated the application of the electrical wire explosion process for synthesis of supported metal catalysts with high thermal stability and activity.

Characteristics of Fe-Cr-Al Alloy Nanopowders Prepared by Electrical Wire Explosion Process under Liquid Media

Fe-Cr-Al alloy nanopowders were successfully prepared by electrical wire explosion method in ethyl alcohol media. The formation of Fe-Cr-Al alloy nanopowder was monitored by X-ray diffraction. The alloy powders have spherical shape and nanometer size. The alloy powders prepared by the electrical wire explosion method have main crystal structures of bcc Fe-Cr alloy. The geometric mean diameter and geometric standard deviation of an alloy powder formed from a wire with diameter of 0.1 mm were 10.2 nm and 1.62, respectively. However, the geometric mean diameter and geometric standard deviation of an alloy powder formed from a wire with diameter of 0.2 mm were 15.4 nm and 1.66, respectively. These values indicate that the particle size of the alloy powders prepared by the EWE method was increased with wire diameter. Fe, Cr, and Al components are uniformly dispersed inside the powder.