Wire Parameters Research Articles

Standardization of metal coil configuration in thermoacoustic imaging

Existing TAI systems mostly use metal wires to calibrate their spatial resolution. However, research on the imaging mechanism of the metal wire and the setting of the wire parameters that can affect the system’s spatial resolution is not sufficient in this context. In general, there is a lack of understanding of the factors affecting spatial resolution. A TAI system, consisting of parallel plate irradiation structures has been developed. Results show that the source of the thermoacoustic signals is the ohmic loss generated by the induced electromotive force. Moreover, the pulse width of the induced electromotive force signal is narrower than that of the system excitation signal, which holds the potential benefits for improving the spatial resolution of the TAI.

Properties of Wedge Wire Bonded Connection Between a Composite Copper Core Aluminum Shell Wire and an 18650 Cylindrical Lithium-Ion Battery Cell

Wedge wire bonding is a solid-state joining process that uses ultrasonic vibrations in combination with compression of the materials to establish an electrical connection. In the battery industry, this process is used to interconnect cylindrical battery cells due to its ease of implementation, high flexibility and ease of automation. Wire materials typically used in battery pack manufacturing are pure or alloyed aluminum and copper. While copper wires possess better electrical properties, the force used in the bonding process can lead to cell isolator damage and cell thermal runaway. This is an unacceptable result of the bonding process and has led to the development of new types of composite wires containing a copper core embedded in an aluminum shell. This material has the advantage of high copper electrical and thermal conductivity combined with less aggressive bonding parameters of the aluminum wire. The aim of this study was to establish a process window for the wedge wire bonding of 400 µm composite copper–aluminum Heraeus CucorAl Plus wire on the surface of a BAK 18650 battery cell. This study was conducted using a Hesse Bondjet BJ985 CNC wire bonder fitted with an RBK03 bond head designed for the bonding of copper wires. The methods used in this study included light and scanning electron microscopy of bond and battery cell cross-sections, shear testing on the XYZtec Sigma bond tester system, and energy dispersive spectroscopy. The results were compared with a previous study conducted using a wire of the same diameter and made out of high-purity aluminum.

A novel subsurface damage model in diamond wire sawing of silicon wafers

The subsurface damages (SSDs) generated during fixed abrasive diamond wire sawing (DWS) of silicon wafers can reduce the fracture strength and increase the breakage probability of these wafers. It is crucial to accurately evaluate these SSDs. A theoretical model of SSD depth is developed for the fixed abrasive DWS of silicon wafers considering the size effects of material properties, micro-geometries of abrasive grits, and inclination/interaction effects of subsurface cracks. A series of silicon wafers are processed, and the silicon material properties, diamond wire parameters, and surface/subsurface morphologies of silicon wafers are measured. The model is experimentally validated and then used to study the effects of processing parameters on inclination/interaction effects, cutting behaviors, and SSDs. The results show that the model has a relative error of less than 5.0% after revealing that the inclination/interaction parameters, cutting behavior parameters, and SSD depth almost follow a normal distribution, with a maximum distribution probability ranging from 30% to 50%. The average inclination angle is approximately 30°, the average cutting depth is in the range of one to two hundred micrometers, the average load is a few millinewtons, and the SSD depth is in the range of a few micrometers. With an increasing density of abrasive grit, a decreasing feed rate, or an increasing wire speed, the interaction effect becomes more pronounced, while the inclination angle, cutting depth, load, active grit ratio, and SSD depth decrease. When the protrusion height increases, or the half sharpness angle or tip radius of abrasive grit decreases, there is an increase in the cutting depth, load, active grit ratio, or SSD depth. The inclination angle decreases as the protrusion height, half sharpness angle, or tip radius increases. This research helps to understand the cutting mechanism and evaluate the SSDs during the DWS of silicon wafers.

Experimental study on spheroidal morphology of palladium coated copper wire with different palladium layer thickness

Palladium (Pd) coated copper (PCC) wire is an emerging bonding wire that has been widely researched. In this paper, the effects of electronic flame-off (EFO) current and EFO time on the free air ball (FAB) morphology of four PCC wires with Pd layer thicknesses of 60, 80, 100, and 120 nm, respectively, are first investigated. The larger the EFO current or the longer the EFO time, the larger the FAB diameter. The EFO time or EFO current setting is either too high or too low to form a FAB with good morphology. Taking the ratio of FAB diameter to wire diameter as 2 as the standard, the EFO current of 48 mA and the EFO time of 700 μs are selected as the optimal EFO parameter combination. Under this parameter combination, the symmetry, roundness, and surface smoothness of the FAB of the four PCC wires are all at a better level. It is found that the FAB surface Pd coverage of PCC wire with 120 nm Pd layer thickness is higher through the corrosion test. The Pd transfer law on the FAB at different EFO times under optimal EFO current is also studied. The results show that with the prolongation of the EFO time, the Pd on the FAB surface is gradually transferred from the neck to the middle and lower parts. This study can provide technical reference for the selection of Pd layer thickness and EFO parameters of PCC wire.

Design of dual-layer heater based on genetic algorithm to optimize magnetic field gradient in vapor cell

Addressing the constraint of magnetic field gradients in the vapor cell on enhancing the sensitivity of atomic magnetometers, this paper proposed a dual-layer heater design based on genetic algorithms, effectively reduced the magnetic field gradients within the vapor cell. The study analyzed the influence of key parameters of the resistive wire, such as wire width, thickness, and spacing, on magnetic noise generation in the three-dimensional model of the heater. The parameter combinations were then optimized synchronously using genetic algorithms to reduce the magnetic field gradient in the vapor cell region and enhance the magnetic noise self-suppression capability of the heater. The simulation results confirmed that the magnetic field strength in most areas remains below 40 pT, and the magnetic field gradient was well-managed. Additionally, further magnetic field experiments demonstrated that the heater's current-generated magnetic field had a strong self-suppression effect on magnetic noise, as evidenced by the index k value of -0.05. This paper provides convincing technical support and experimental evidence for improving the performance of the SERF atomic magnetometer.

The sensitivity analysis of geometric parameters on the power cycling reliability of bond wires

Considering the reliability of the bond wire comes as the main factor determining the reliability of power devices at present, and the geometric parameters of the bond wire have an in-negligible effect. A Finite Element (FE) simulation model based on a discrete device with TO-247 package and a single bond wire is established in this paper, and the influences of the geometric parameters are analyzed, which include the joint length L, the diameter D, and the aspect ratio λ. Then to understand the influence degree of the parameter on the reliability, the sensitivity analysis of these geometric parameters is carried out based on the sobol' method, using the Monte Carlo method for estimating the sensitivity index. The results show that increasing the joint length L, the diameter D and the aspect ratio λ all have a negative impact on the bond wire reliability, while a positive influence is presented by increasing the aspect ratio λ in the case without epoxy mold compound (EMC). This is because of the EMC's protective effect which inhibits the bond wire's thermal expansion. The aspect ratio λ is the most sensitive parameter of the three geometric parameters since it has the largest total sensitive index.

Design exploration of the status detection system for car-mounted catenary tension compensation device

The tension compensation device is a critical component for maintaining constant parameters of the contact wire, such as tension, catenary height, and sag, in the overhead contact system. Its operational status directly affects the normal operation of the entire contact wire system. This paper provides a comprehensive review of existing tension compensation device state detection techniques and analyzes their shortcomings. By comparing with existing methods for monitoring cable tension, a vehicle-mounted contact wire tension compensation device state detection system based on the three-point bending method is proposed. This system can simultaneously monitor the operational status of the device at the line side and anchor section, issuing real-time warnings in case of abnormal device states and possessing significant application value. This study provides a reliable tool for railway operators to monitor the devices status and take timely maintenance and adjustment measures to ensure the normal operation of the contact wire system

Wire Bow In Situ Measurement for Monitoring the Evolution of Sawing Capability of Diamond Wire Saw during Slicing Sapphire.

Electroplated diamond wire sawing is widely used as a processing method to cut hard and brittle difficult-to-machine materials. Currently, obtaining the sawing capability of diamond wire saw through the wire bow is still difficult. In this paper, a method for calculating the sawing capability of diamond wire saw in real-time based on the wire bow is proposed. The influence of the renewed length per round trip, crystal orientation of sapphire, wire speed, and feed rate on the wire sawing capability has been revealed via slicing experiments. The results indicate that renewing the diamond wire saw, and reducing the wire speed and feed rate can delay the reduction in sawing capability. Furthermore, controlling the value of renewed length per round trip can make the diamond wire saw enter a stable cutting state, in which the capability of the wire saw no longer decreases. The sawing capability of diamond wire saw cutting in the A-plane of the sapphire is smaller than that of the C-plane, and a suitable feed rate or wire speed within the range of sawing parameters studied in this study can avoid a rapid decrease in the sawing capability of the wire saw during the cutting process. The knowledge obtained in this study provides a theoretical basis for monitoring the performance of the wire saw, and guidance for the wire cutting process in semiconductor manufacturing. In the future, it may even be possible to provide real-time performance parameters of diamond wire saw for the digital twin model of wire sawing.

Development of a computational system to design a helical spring

AbstractSprings are the most basic mechanical elements used in transmission mechanisms. The rapid development of the computer and cellular industry has encouraged spring manufacturers to develop the industry to produce very small springs. Most computer-aided design programs for mechanical parts provide the possibility of designing these parts, as these programs include different types of decisions. All these decisions require coordinates for geometric data as well as metadata. The paper aims to develop software programs to design and analyze springs as one of the most significant mechanical elements used. This paper aims to develop a design software of a helical spring system, where this software is built using a computer program in the language of Visual Basic Version 5. When the user enters data into the system, the system will perform a series of complex calculations in the system, then provide a detailed report on all the engineering dimensions of the spring, and test its efficiency. The output of the software shows the required spring wire parameters. The software was tested with test data from the open literature, and the required wire spring parameters were obtained.

Research on self-leakage flux magnetic identification method of the most dangerous section of parallel wire cable under multi-point broken wire condition

The self-leakage magnetic signal of 37 parallel steel wires was detected by using magnetic signal detection technology and equipment. Based on the theoretical and experimental data, the relationship between the magnetic signal characteristics and the influencing factors was analyzed. The magnetic signal characteristics of multi-point interleaved broken wires are explored. The results show that the characteristics of the self-magnetic flux leakage signal of parallel wires broken are related to the defect parameters of the broken wires. The influence of lifting height on the magnetic signal is less than 3.8 %. The influence rate of the detection angle path is under 8.3 %. By analyzing the measured magnetic signals, a method for identifying the most dangerous cross section is proposed, and this is modified and improved. The maximum identification error of the recognition error is only 5.6 %.

Realization of experimental teaching of Young modulus based on finite element method

Young modulus experiment is a frequent item in university physics experimental courses, and in the process of doing Young modulus experiment, we will encounter problems such as difficulty in adjusting the device, difficulty in reading, and easy to break the wire line. This teaching method is based on the finite element method, which allows students to simulate and model Young modulus in CAE software after understanding the principle of Young modulus experiment. Modeling can deepen students’ understanding of Young modulus experiment. Adjusting the Young modulus of the model, the length and diameter of the wire and other parameters can quickly solve different experimental results and cultivate students’ research thinking.

Enhancing Wireless Power Transmission Efficiency via Resonant Coupling into Coil and Wire Parameters

The concept of wireless power transmission involves the transfer of electrical energy from a power source to an electrical load without wires. The technology has become widely used in various mobile, industrial, and medical fields. This innovation eliminates the need for wires and batteries, making it a convenient and safe option for all users. Inductive and resonant coupling are the most commonly used methods for wireless power transmission. This work delves into designing and developing wireless power transmission hardware. A wireless power system comprises a transmitter (primary coil) and a receiver (secondary coil). The primary coil produces a magnetic field by passing alternating current through it. The secondary coil is then positioned close to the primary coil. When the two devices make contact, the primary and secondary coils become magnetically linked, causing the power to transfer from transmitter to receiver. To optimize the wireless power transmission using a resonant coupling, the paper tests and analyzes how different wire diameters, coil diameters, and the number of coils affect the output power.

Study of the influence of the parameters of modern grounding wires on the value of power losses in them for overhead power lines of 330-750 kV

Introduction. The problem of estimating power losses in grounding wires with built-in fiber optic cable for overhead power lines of voltage class 330-750 kV is relevant, while it is obvious that the amount of losses depends on the chosen brand of wire. Problem. In the article, an analysis of the influence of the parameters of grounding wires on the amount of losses that occur in them in the normal mode of operation of the overhead power lines is carried out. Goal. The purpose of the work is to determine the criterion for the selection of grounding wires with a built-in optical fiber cable under the condition of increasing the energy efficiency of electricity transmission. Methodology. To calculate power losses in grounding wires, the methods of electromagnetic field theory were used, while taking into account the location of phase conductors on various types of towers of operating 330-750 kV overhead power lines and the possible current load of such lines. Results. The paper analyzed the dependence of losses in the grounding wires of the overhead power lines on the ratio of its active and reactive resistances, determined in which range of this ratio the losses will be close to the maximum. It is shown that the amount of specific power losses in the grounding wires of 330-750 kV overhead power lines in its normal operating modes can range from 1.6 kW/km for the 750 kV lines to hundreds of W/km for the 330 kV power lines. Originality. For the first time, it is recommended to use grounding wires with built-in fiber optic cable with running active resistance in the range of no more than 0.25 Ohm/km, which will minimize power losses and increase the energy efficiency of the 330-750 kV overhead power lines. Practical value. The obtained results can be applied at the stage of designing new or modernizing existing overhead power lines in order to reduce losses and increase the energy efficiency of lines.

Prediction of Microwave Characteristic Parameters Based on MMIC Gold Wire Bonding

In this paper, a method based on deep learning is proposed to predict the parameters of bonded metal wires, which solves the problem that the transmission characteristics of S-parameters cannot be predicted. In an X-band microwave chip circuit, gold wire bonding technology is often used to realize bonding interconnection, and the arch height and span of the bonded metal wire will have a great influence on the microwave transmission characteristics. By predicting the S-parameters of the bonded metal wire, the relationship between the structure parameters of the single wire and the transmission performance of the microwave device can be deduced. First, the gold wire bonding model is established in HFSS simulation software. After parameter optimization, the simulation results meet the requirements of establishing data sets. Then the sampling range of S parameters is set, and the parameters are scanned to establish data sets. Second, the artificial neural network model is built. The model adds a dropout mechanism to the hidden layer to enhance the generalization of the neural network, prevent overfitting phenomenon, and significantly improve the model’s prediction performance. Finally, the model predicts the corresponding relationship between the arch height and span of the bonding wire and the insertion loss, return loss and standing wave ratio. The mean square error of the test set is less than 0.8. The experimental results show that compared with the traditional process measurement method, this method can quickly and accurately infer whether the microwave characteristics of the bonded product are qualified, which greatly reduces the time and economic cost of the engineer and improves the work efficiency.

Input density tunes Kenyon cell sensory responses in the Drosophila mushroom body.

The ability to discriminate sensory stimuli with overlapping features is thought to arise in brain structures called expansion layers, where neurons carrying information about sensory features make combinatorial connections onto a much larger set of cells. For 50 years, expansion coding has been a prime topic of theoretical neuroscience, which seeks to explain how quantitative parameters of the expansion circuit influence sensory sensitivity, discrimination, and generalization. Here, we investigate the developmental events that produce the quantitative parameters of the arthropod expansion layer, called the mushroom body. Using Drosophila melanogaster as a model, we employ genetic and chemical tools to engineer changes to circuit development. These allow us to produce living animals with hypothesis-driven variations on natural expansion layer wiring parameters. We then test the functional and behavioral consequences. By altering the number of expansion layer neurons (Kenyon cells) and their dendritic complexity, we find that input density, but not cell number, tunes neuronal odor selectivity. Simple odor discrimination behavior is maintained when the Kenyon cell number is reduced and augmented by Kenyon cell number expansion. Animals with increased input density to each Kenyon cell show increased overlap in Kenyon cell odor responses and become worse at odor discrimination tasks.

Investigation of the effect of compacting mode parameters of a carbon-aluminum wire preform on the strength of the produced compact

The effect of the modes of compaction of a carbon-aluminum composite of a wire preform on its microstructure, properties, and nature of fracture has been studied. It is shown that with an increase in the temperature, load, and holding time, the volume fraction of pores decreases, and the fraction of fiber increases, which leads to an increase in the composite strength. In all cases, the shape of the fracture surface indicates the brittle nature of the composite fracture.

Study on subsurface microcrack damage depth of diamond wire as-sawn sapphire crystal wafers

Sapphire crystals are widely used as window materials for infrared emitting devices, high intensity lasers, optical elements and microelectronic substrates due to the excellent material properties. The subsurface microcrack damage produced by diamond wire saw when cutting sapphire crystal is an important indicator of the cutting quality. In this paper, diamond wire sawing experiments were conducted within the industrial production processing parameters to investigate the as-sawn sapphire crystal wafers subsurface microcrack damage depth (SSD), and a numerical calculation model was established to predict the SSD based on the analysis of the scratching stress field of single abrasive. The effects of the saw wire speed and specimen feed speed, saw wire parameters on SSD were predicted. The results show that, within the parameters studied in this paper, the material was removed in brittle mode, increasing the saw wire speed (from 1000 m/min to 1600 m/min) and reducing the specimen feed speed (from 0.5 mm/min to 0.05 mm/min) can reduce the sapphire as-sawn wafers SSD, reduce the size of brittle tear-shape edge breakage, the number and size of brittle pits on the as-sawn wafer surface are reduced and the surface morphology consistency is improved. Increasing the abrasive density and reducing the abrasive size can reduce the SSD. The study results provide a reference for the reasonable matching of sawing process parameters and saw wire parameters in industry.

Investigation of photon interaction parameters of alloys used in orthodontic treatments for dental radiology applications

In the present study, it was aimed to examine the photon interaction parameters of some alloys used in orthodontic treatments in dental and medical radiology energies. First of all, a transmission geometry consisting of 241Am (100 mCi) radioactive source and Ultra Ge detector was established to experimentally obtain the mass attenuation coefficients (μρ, cm2/g) of Beta Titanium (BT), Copper NiTi, NiTi (Nitinol) and stainless steel (SS) alloys, which are frequently used as orthodontic wires. The experimental μρ values in the energy range of 13.9–59.54 keV with the data obtained from the spectra were compared with the theoretical results generated with the EpiXS program. The μρ values at 59.54 keV were 0.760, 0.933, 0.924 and 1.315 cm2/g for BT, NiTi, Copper NiTi and SS, respectively. Based on μρ values, HVL and Zeff values were also obtained. The HVL values for BT, NiTi, Copper NiTi and SS at 59.54 keV were calculated as 0.203, 0.135, 0.138, 0.066 cm, respectively. Then, the buildup factor values of the alloys in the energy range of 0.015–15 MeV were calculated at penetration depths of 1–15 mfp. When all the results are evaluated together, SS is more effective in absorbing photons, while BT is the alloy with the highest photon buildup among the alloys studied. Besides, it is noteworthy that the alloys cause secondary scatterings. The data obtained from this study will provide information about the photon interaction parameters of orthodontic wires in dental and medical radiology applications.

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.

Operability evaluation of electrical wires and cables subjected to simultaneous fire and current loadings

Introduction. Intumescent coatings are used as a means of protection from heat flows, and their mission is to preserve the operability of wires and cables under fire conditions coupled with simultaneous current loading. However, the effect of insulation destruction on the operability of cables has not been studied for the case of a real fire regime.Goals and objectives. The purpose of the article is to evaluate the experimental operability of electrical wires and cables subjected to simultaneous effects of fire and current loadings.To achieve this purpose, an experimental testing unit was applied to conduct the experimental testing of wires and cables manufactured by various producers. At the same time, the temperature effect of the heated environment on electrical parameters of wires and cables, such as resistivity, inductance and capacitance, was evaluated.Theoretical background. In real fire conditions, dependence of indoor temperature, affecting the heating of cable insulation, differs essentially from the same dependencies in cases of various standard fire conditions. Therefore, the insulation destruction process may occur before the coating intumescence starts.Results and discussion. An experimental testing unit has been developed. This unit allows for the gradual cable heating with a pre-set temperature measurement interval and cable electrical characteristics. Dependencies of resistivity, inductance and capacitance of standard electrical cables on the temperature of the air surrounding the cable are obtained. It’s been discovered that the gradual heating of an electrical conductor or cable eventually leads to a short circuit between its conductive cores and further electric current transmission in electrical wires and cables. It is shown that phases and amplitudes of an input electrical signal can drastically change before the short circuit.Сonclusions. The simultaneous effect of fire and current loadings on standard electrical wires and cables causes a short circuit in the temperature range, in which no intumescence of flame retardant coatings is initiated on the insulation surface. Therefore, these coatings can ineffectively maintain the operability of electrical wires and cables.