Wire Cross Section Research Articles

Magnetoimpedance effect in NiFeP thin films deposited on Cu microwire through electrodeposition

Thin coatings of the Nickel–Iron–Phosphorous (NiFeP) alloy is electrodeposited onto copper microwire while varying phosphorus ion concentration in the bath. With increasing phosphorus ion concentration in the deposition bath up to 1 mM, reduced surface roughness, crystallite size and coercivity is witnessed which reflects in enhanced magnetoimpedance (MI) ratio of the plated wires. Maximum MI ratio of 378% and sensitivity of 25 %/Oe is observed at 100 kHz driving frequency for film deposited using 1 mM of P ion in the electrodeposition bath. This enhancement is associated with the reduction of crystallite size and magnetocrystalline anisotropy due to leading formation of amorphous deposits with the optimized incorporation of P atoms coupled with reduction of surface roughness. Additionally, the experimental results of MI measurements are compared with a analytical model and the model parameters related to the circumferential permeability of the NiFeP magnetic film is extracted from it. These parameters are further used to calculate the circumferential permeability of the samples, which is then mapped to a color-coded visualization of current density variation across the wire cross-section, providing a detailed insight into the impedance change.

Fabrication of a gradient AZ91-bioactive glass composite with good biodegradability

This study used friction stir-back extrusion to fabricate the AZ91 + 3 wt% bioactive glass gradient composite wire. The microstructure, mechanical properties, and corrosion resistance of a material in a simulated body fluid were investigated. Three 2-mm diameter holes with varying hole patterns were drilled in the cross-section of the AZ91 rod to apply 3 wt % bioactive glass to the AZ91 matrix. The results demonstrated that the hole pattern strongly influenced the material's flow in the extruded wire's cross-section. By increasing the distance between the center of the initial rod and the center of the holes, a higher temperature and more uniform distribution of plastic strain are formed during friction stir back extrusion, resulting in uniform distribution of bioactive glass particles and α + β eutectic structure near the surface of composite wires. Introducing bioactive glass particles into the zone near the surface of the AZ91 rod results in the formation of a uniform distribution of bioactive glass particles near the surface and their absence in the central zone of the composite wire. A higher amount of discontinuous β-Mg17Al12 phase and α + β eutectic formed at the grain boundaries by increasing the temperature and plastic strain during friction stir-back extrusion. The crystallographic texture of the AZ91 rod changed from prismatic to basal and pyramidal due to the friction stir-back extrusion method. A gradient AZ91-bioactive glass composite wire with ultimate tensile strength, yield strength, elongation, and corrosion resistance 58, 64, 62, and 34%, respectively, greater than AZ91 as-cat rod can be produced by inserting bioactive glass powder using a hole drilling method and applying a friction stir back extrusion process.

Augmenting the performance of friction stir back extruded AZ91 alloy using the gradient composite design technology

This study investigates the effect of extrusion speed during friction stir back extrusion on the microstructure, mechanical characteristics, and in vitro corrosion behavior of AZ91-3 vol % bioactive glass composite wire. To that end, the bioactive glass powder was inserted into the AZ91 matrix by drilling holes in the cross-section of the AZ91 rod. The results show that the extrusion speed strongly influenced the material's flow in the extruded wire's cross-section. By adding the bioactive glass powder to the processed wire, the ultimate tensile strength and corrosion resistance increased 5 and 23% compared to the additive-free wire. By decreasing the extrusion speed to 20 mm/min, the higher amount of discontinuous β-Mg17Al12 phase and α + β eutectic formed in the grain boundaries. By applying the friction stir back extrusion process on the AZ91 rod a random crystallographic texture formed in the extruded wires. In the composite samples extruded at a rotational speed of 1200 rpm, a traverse speed of 20 mm/min, a gradient distribution, and improvement of mechanical properties (ultimate tensile strength of 332.95 MPa, yield strength of 268.33 MPa, and elongation of 9.89%) and corrosion rate (1.879 mm/year) at simulated body fluid were achieved.

Study of changes in microstructure and metal interface Cu/Al during bimetallic construction wire straining

This article investigates the effect of a new processing technology on the change in microstructure and mechanical properties of bimetallic aluminum-copper wire. This technology makes it possible to produce a new generation of wire for use in the construction of new overhead lines and reconstruction of old ones. The study was conducted using a transmission electron microscope, EBSD analysis, tensile tests, and determination of microhardness and electrical conductivity. The results of the study show that an ultrafine-grained copper-aluminum composite with a gradient structure is formed during straining by ECAP-drawing. Annealing after straining at 200 °C increases the strength of the interfacial connection between Cu and Al and improves the strength characteristics of the bimetallic aluminum-copper wire. The use of such aluminum-copper wires for overhead transmission lines allows to reduce the wire cross-section and, accordingly, wind loads, as well as to increase the strength properties without an additional increase in the total weight of the wire.

Investigation of the stress-strain state of a wire during high-speed monolithic drawing

This article presents the results of analytical studies conducted using computer modeling in the QForm package. The influence of technological parameters of high-speed monolithic drawing on the stress-strain state and strain rate of the wire made of steel grade 10 was assessed. A billet with a diameter of 3.5 mm was drawn into a wire with a diameter of 3.0 mm through monolithic dies with a half-angle of 3; 4; 5; 6; 7 and 8° at a friction coefficient of 0; 0.05 and 0.10. The drawing speed was taken to be 10, 20, and 40 m/s. The analysis has established that increasing the value of the half-angle of the drawing leads to the occurrence of tensile stresses and strains in the surface layers of the wire. The value of the friction coefficient has a significant effect on the stress-strain state of the wire during drawing, increasing its value leads to increased unevenness of deformation along the section and increases the values and depth of penetration of tensile stresses and strains along the wire section. It has been established that the half-angle of the drawing die has a significant effect on the uniformity of the distribution of strain rates over the wire cross section. The maximum strain rate during drawing in monolithic dies can exceed twice the average strain rate. An increase in the die half-angle from 3 to 8° leads to an increase in the strain rate up to 2.5 times. The localization of high strain rates at large half-angles of wires with is concentrated in the central part of the wire. An increase in the drawing speed from 10 to 40 m/s leads to an increase in the strain rate up to 5 times. As a result of the research, it was shown that the QForm package is applicable for computer simulation of the drawing process in a monolithic die. The adequacy of the obtained results of the numerical experiment allows us to recommend it for conducting studies of the effect of technological parameters on the stress-strain state of wire of various assortment

Study of the quality of electric power in electric networks with semiconductor converters

At present, semiconductor converters have found wide application in the electric power industry [6]. One of the most common semiconductor converters is a frequency converter, as it provides a three-phase voltage with adjustable frequency from a three-phase mains voltage. However, it, like other semiconductor converters, is the cause of the appearance of harmonics and, as a result, the non-sinusoidal shape of the voltage curve [1]. Harmonics are the cause of such negative effects in the electrical network as concomitant heating of the windings of motors, transformers, etc., false alarms in distribution networks, asymmetry in industrial networks with three-phase sources when harmonics occur in one phase, the occurrence of noise in communication networks, the influence on adjacent low-current and power cables due to the induced EMF, and also with the appearance of harmonics, there is a need to increase the cross section of neutral wires due to the summation of harmonics multiple of the 3rd in three-phase networks [3]. Therefore, the study of the harmonic components of the voltage is an urgent task.
 Subject of research: processes occurring in electrical networks with a frequency converter.
 Purpose of research: to identify the presence of harmonic voltage components in electrical networks with a frequency converter.
 Object of research: a research stand that simulates the operation of electrical networks with a frequency converter.
 Methods of research: in the process of performing research, scientific and technical generalization of literary sources on the initial prerequisites for research, methods of the theoretical foundations of electrical engineering and the theory of electrical networks, the method of analytical research, methods of system analysis were used. Experimental studies were carried out by a complex method using the Resurs-PKE device.
 Results of research he study: based on the studies carried out, it was shown that the frequency converter is a source of harmonic voltage components, while harmonics appear only in certain sections of the electrical circuit.

Two-Phase Flow Coordination Characteristics of H62 Brass Alloy Prepared by Up-Drawing Continuous Casting

In this study, the two-phase flow coordination characteristics between α and β phases of H62 brass made by up-drawing continuous casting are investigated based on the upsetting process. An in situ and new research method for two-phase flow is put forward, and the two-phase flow and grain refinement characteristics are observed under different deformation conditions. The results show that α phase flows fast under 400 °C, β phase is pulled and overridden by α phase under this temperature. When the temperature increases to 500 °C, which is higher than β phase transition temperature, the flow velocity of β phase increases, and the deformation of β phase is found to bulge. The flow of β phase is more sensitive to low deformation rates than α phase. The deformation amount has a more significant impact on β phase than α phase, and the deformation of β phase promotes the grain fragmentation and refinement of α phase accompanied by huge β phase bulging obviously. Under the conditions of high temperature, low deformation rate, and large deformation amount, both phase α and β of up-drawing continuous casting brass alloy are broken and the grains are refined. Based on the two-phase flow characteristic, numerical simulation is used to obtain the optimal continuous extrusion parameters of the H-shaped wire of up-drawing continuous casting H62 brass. Then, the optimized complex cross-section wire is prepared by continuous extrusion experiment. This research aims to provide guidance for the complex processing of two-phase alloys.

Development and characterization of atom chip for magnetic trapping of atoms

In this work, we report the development and characterization of an atom chip for magnetic trapping of cold 87Rb atoms. For fabrication of the atom chip, a silicon substrate was used after depositing an insulating layer of silica (SiO2) on it. An adhesive chromium layer was further deposited on this substrate before the deposition of the final layer of gold. On this gold coated substrate, a z-shaped gold wire (cross section, 500×2.5μm2) was fabricated by a photo-chemical machining method. The chip wire was tested for current–voltage characteristics for its reliable operation in magnetic trapping. The atoms from an U-magneto-optical trap, after optical pumping, were directly trapped in the magnetic trap of the atom chip.

Experimental Determination and Calculation of the Wire Drawing Force in Monolithic Dies on Straight-Line Drawing Machines

In this article, a mathematical model has been developed for calculating the energy-power parameters of the drawing process in monolithic dies on straight-line drawing machines, and its adequacy has been validated in experimental wire drawing on a laboratory automated drawing machine. The program allows us to calculate drawing stress, drawing force, tensile strength and yield strength of the alloy after wire drawing, safety factor, and drawing power. The developed mathematical model differs in that it allows us to evaluate the uniformity of deformation over the wire section, depending on the technological parameters of the deformation zone, namely, the semi-angular die, the coefficient of friction and the degree of deformation. To select the technological parameters of the deformation zone, which ensure uniform deformation over the wire cross-section, a nomogram was compiled. The equations of hardening during nickel NP2 wire drawing are obtained. The calculation of energy-power parameters of drawing nickel NP2 (Ni 99.6) wire ∅1.8 mm from ∅4.94 mm wire rod is given. Experimental studies have been carried out to determine the energy-power parameters of nickel wire drawing on a laboratory drawing machine with an installed ring strain gauge to determine the drawing force. A change in the friction coefficient by 0.02 when drawing nickel wire leads to an increase in stress and drawing force by 20%. To improve the accuracy of the developed mathematical model, it is shown that in the future, it would be necessary to conduct experimental studies on a laboratory drawing machine to determine the effect on the energy-power parameters of the drawing process of the values of technological parameters entered into the program as constant real values, such as the friction coefficient, die half-angle, drawing speed, and back tension.

Effect of discharge accumulation on wire breakage in WEDM process

In recent years, WEDM has been adopted in precision machining as an important alternative machining method because of its greater flexibility and lower wear cost compared with traditional machining, whereas wire breakage during WEDM is an unignorable problem that influences the machining quality and efficiency. Therefore, it has been a research topic of considerable interest. This work focuses on exploring the reason for the wire breakage. Firstly, by observing the wire after discharges and using the finite element method, a complete thermal model considering both latent heat and flushing efficiency was built. With this model, the simulation of the crater on the wire was finished. Then based on the result gotten from the simulation and experiment, the heat partition ratio to the wire was found as 46.74% by inverse fitting. After that, a wire breakage experiment was done and through locating the position of 50 discharges before wire breakage it is found that 34% of discharges were located within a range of 2 mm, and the minimum area in the wire cross-section only remained 41.88% compared with the original wire. This kind of decrease in the cross-section area made the stress higher than the UTS of the wire and caused the wire breakage. The findings of this work allow for a more in-depth understanding of the effect of discharge accumulation on wire breakage.

The use of additive technologies for the restoration and strengthening of parts of transport means

The article is devoted to the comprehensive development and implementation of multifunctional coatings obtained through the use of additive technologies, based on scientific research in the field of restoration and strengthening of worn parts to increase the resource of transport means and their elements, aimed at reducing the material and technical resource and reducing the supply of spare parts. When choosing a method of gas thermal spraying, the main conditions for the formation of high-quality coatings are established, and it is proved that the method of electric arc spraying best meets these conditions. The conducted assessment showed that to restore and strengthen the surfaces of parts of ship's technical equipment, it is expedient to replace expensive powder-coated wires made of highly alloyed alloys with cheaper and more affordable steel wires of a solid cross-section made of iron-carbon alloys. The obtained research results of coatings applied by the electric arc method showed the prospects and feasibility of their processing by pulsed ion nitriding. As a result of the conducted research, for the first time, a method of increasing wear resistance was proposed and developed, which provides an increased level of physical and mechanical properties of restored surfaces and a comprehensive solution to the problems of ensuring the characteristics of strength and operational properties of restored surfaces and developing a technological process of restoring parts of ship's technical equipment.

INCREASING THE CAPACITY OF ELECTRICAL TRANSMISSION LINES IN THE POST-EMERGENCY MODE

Automatic switching on of the reserve (AVR) points are used to increase the reliability of power supply to consumers, which are advisable to install in distribution power networks and consumer networks for the power supply of production processes, the technology of which does not allow even short-term interruptions in power supply. The purpose of the research: substantiating the location of the AVR point for mutual redundancy of power transmission lines; determination of the effect of longitudinal capacitive compensation on the transmission capacity in the post-emergency mode; determining the impact of reactive power compensation on the economy of the post-emergency power transmission mode. The article considers a method of increasing the capacity of power transmission in the post-emergency mode, as a result of which an adjacent (reserved) line is connected to one of the working power transmission lines with a voltage of 10 kV using the point of automatic switching on of the reserve (AVR). However, the effectiveness of such redundancy in most cases turns out to be low due to the limited capacity of trunk sections of mutual-reserved lines with smaller cross-sections of wires at the end sections of both mutually-reserved lines, which were built as radials. As a result of such redundancy, there are increased losses of active power and voltage, and, as a result, unacceptable deviation of the voltage in remote nodes of the load of the redundant power transmission line. In order to improve the parameters of the operation mode of power transmission, it is proposed to use devices of longitudinal capacitive compensation and reactive power compensation in the scheme of the AVR point.

Mechanical enhancement and weakening in Mo6S6 nanowire by twisting

The torsional, bending and tensile mechanical properties of Mo6S6 nanowire are examined by molecular dynamics (MD) simulations with a first-principles-based reactive force field (ReaxFF). It is found that Mo6S6 nanowire shows unique mechanical properties such as high torsional and bending flexibility, high Young’s modulus and strength, and negative Poisson’s ratio. The Mo6S6 nanowire can be strengthened or weakened via twisting, depending on the twist angle. The Mo6S6 nanowire with a slight twist angle shows brittle failure, whereas it with a large twist angle exhibits ductile failure and necking behavior. Twisted Mo6S6 nanowires show a crossover in the negative Poisson’s ratio at critical strains, that is, Poisson’s ratio first decreases but then increases, with a minimum value down to around −0.8 at the strain of 0.01 as the twist angle is 21.0 °/nm. The negative Poisson’s ratio and the crossover are explained by the bond transform that makes zero angles to the wire cross-section.

Cryogenic reciprocating torsion induced nanoscale precipitation in aluminum wire with exceptional strength and electrical conductivity

Cryogenic reciprocating torsion (CRT) was used to trade off strength and electrical conductivity in aluminum wires. Compared with the initial sample, the CRT processed aluminum wires possess higher strength without significant sacrifice of electrical conductivity. The ultimate tensile strength increases by 76% with a slight decrement of 1% IACS in electrical conductivity. Microstructural characterizations show that CRT induces multiple gradient structures (MGSs) on the cross-section of aluminum wires: dislocation density gradient, grain size gradient, and precipitate size gradient. In particular, a bimodal distribution of precipitate size was observed in CRT processed aluminum wires. A theoretical model considering the above microstructures was proposed to explain the excellent properties. The experimental results validate the reasonability of the present model. The further theoretical analyses reveal that nanoscale precipitates contribute more to the exceptional strength and electrical conductivity than other microstructures.

Dynamical signatures of point-gap Weyl semimetal

We demonstrate a few unique dynamical properties of point-gap Weyl semimetal, an intrinsic non-Hermitian topological phase in three dimensions. We consider a concrete model where a pair of Weyl points reside on the imaginary axis of the complex energy plane, opening up a point gap characterized by a topological invariant, the three-winding number $W_3$. This gives rise to surface spectra and dynamical responses that differ fundamentally from those in Hermitian Weyl semimetals. First, we predict a time-dependent current flow along the magnetic field in the absence of an electric field, in sharp contrast to the current driven by the chiral anomaly, which requires both electric and magnetic fields. Second, we reveal a novel type of boundary-skin mode in the wire geometry which becomes localized at two corners of the wire cross section. We explain its origin and show its experimental signatures in wave-packet dynamics.

Relation between constituent material fraction in multifilamentary MgB2 wires and requirements for MRI magnets

Magnetic resonance imaging (MRI) occupies the largest segment of the commercial applications of superconductivity. The NbTi wire is typically applied to MRI magnets and fulfils their strict requirements. On the other hand, the dramatically large energy margin in the MgB2 wire is attractive for liquid helium-saving MRI magnets. However, there are many types of cross-sections in the MgB2 wires. This makes it difficult to analyse the applicability of the MgB2 wires to the MRI magnets systematically. This paper focuses on the in situ MgB2 wires with an iron matrix and a Monel reinforced member. Multiple evaluations are conducted for several types of MgB2 wires, and their applicability to the MRI magnets is discussed. Because the critical current density of the superconducting filaments does not largely depend on the cross-section of the wires, the engineering critical current density (J e) is roughly proportional to the superconducting fraction (λ sc). The acceptable bending strain of the heat-treated wires increases with the Monel fraction and is in the range of 0.3%–0.65%, which is larger than the value required for coil winding of the MRI magnets. Two types of protection approaches of the magnet are considered. One is an active protection. This approach requires a large fraction of the copper stabilizer in the cross-section of the wire and relatively reduces λ sc and J e. The other is the avoidance of quenches over the product lifetime using quick ramp-down of the magnet for unfortunate events, such as cooling system failure and emergency rundown. This approach requires no copper stabilizer and increases λ sc and J e thus widens the acceptable operational temperature range. The cross-section of the MgB2 wire can be designed with a certain level of freedom depending on its functional requirements.

Asymmetric dual Bloch point domain walls in cylindrical magnetic nanowires

Cylindrical magnetic nanowires have been studied extensively over the past ten years due to the presence of domain walls with novel topology and outstanding dynamic properties. In soft magnetic systems, where shape anisotropy forces the magnetization along the wire axis, and for radii above 50 nm, two topologically distinct walls have been previously identified. The Bloch point wall (BPW) has a circulating magnetization texture around the circumference and contains a single Bloch point within the center of the wire cross section. In contrast, asymmetric transverse walls (ATWs) have a circulating magnetization structure on the surface and contain two topological defects, a vortex and an anti-vortex on opposing sides. These surface defects are connected via a vortex tube that penetrates the volume. In this study, we have numerically investigated the domain wall magnetization textures for nickel nanowires of radii 50–120 nm. Beyond reproducing the known BPW and ATW topology, we discover a new domain wall type that contains aspects of both. This new domain wall type, which we call asymmetric dual Bloch point wall (ADBPW), has surface vortices similar to an ATW and two Bloch-point textures adjacent to the internal vortex tube. Time-resolved simulations investigating the stability of ADBPW show its field-driven transformation into a BPW via the ejection of a single Bloch point at the surface and subsequent annihilation of surface vortices.

Steel Wire Mechanical Property Degradation Study Based on Numerical Simulation

With the rapid development of underground engineering construction, such as deep mining of mineral resources and tunnel excavation under complex geological conditions, the existing support methods cannot meet the deformation requirements. It is necessary to conduct in-depth research on the stress status and damage evolution of the hanger rods, to establish a theoretical basis for the design principles and criteria of key components. In this paper, the degradation law of the mechanical properties of the hanger steel wire with the degree of corrosion is analyzed in detail. The results show that the corrosion changes the geometry of the cross section of the steel wire, which leads to the degradation of the mechanical properties of the steel wire. With the increase of corrosion length and depth, the strength, stiffness, and ultimate strain of the steel wire are reduced to varying degrees, and the effect of pitting corrosion is more significant than that of uniform corrosion. The closer the holes are, the greater the corrosion effect is.

ТЕХНІКО-ЕКОНОМІЧНЕ ОБҐРУНТУВАННЯ ВИБОРУ КОНСТРУКЦІЇ ФАЗИ ТА ПЕРЕРІЗУ ПРОВОДУ ПОВІТРЯНОЇ ЛІНІЇ ЕЛЕКТРОПЕРЕДАЧ

The paper analyzes the existing method of choosing the cross-section of wires by the method of an interval of economic curves. It is shown that the cross-section of the wires and the design parameters of the lines must correspond to the ratio between the cost of construction and the cost of optimizing the design of phase wires. The algorithm of application of this method for 330 kV power transmission lines with split phase is substantiated. A current load search algorithm has been developed and proposed, in which it is assumed to switch to the use of split-phase wires with minimal costs. Many arrays of curves are constructed, which allows for choosing the cross-section of wires and the conditions under which it is necessary to split the phase wire. Algorithms for selecting economically feasible wire cross-sections and methods for determining the conditions of profitability of overhead power lines are presented. The optimization of the cross-section and construction of the line phases was carried out, and the conditions of expedient phase splitting and application of lines of increased natural power were determined. The least-squares method was used to approximate the lower envelope. Ref. 9, fig. 3, table.

Comparative investigation of fully customized lingual bracket systems and conventional labial appliances: Analysis of forces/moments and final tooth positions

The assessment of forces and moments generated by fully customized lingual appliances and their effectiveness in tooth movement were compared with conventional labial bracket systems, applied to a specific malocclusion model. Two fully customized lingual appliances (Incognito [3M Unitek, Monrovia, Calif] and WiN [DW Lingual Systems, Bad Essen, Germany]) and 2 labial bracket systems (Discovery classic and Discovery smart [Dentaurum, Ispringen, Germany]) were examined with nickel-titanium wires of different cross-sections (0.012, 0.014, 0.016, and 0.016 × 0.022-in) and 3 tooth types (canine, lateral incisor, and second premolar). Simulated movement was performed with a wire replacement as soon as forces or moments were no longer effective. Lingual and labial appliances showed statistically significant differences in initial forces and moments when tested with the same cross-section wires. Statistically significant differences between the 2 lingual bracket systems were also registered. Both lingual appliances rotated the premolar less than the conventional labial appliances. In areas of smaller lingual interbracket distance and higher lingual slot misalignment, the tested lingual multibracket appliances showed higher forces than the labial appliances. The force difference was particularly prominent with vertically oriented lingual slots and rectangular wires. The tested lingual appliances presented difficulties in rotating the premolar.