Wire Core Research Articles

Practical Method for Drastic Improvement of Output Offset Stability in Bias-Switched Fundamental Mode Orthogonal Fluxgate

Fundamental mode orthogonal fluxgate (FM-OFG) adopting the bias switching technique is a promising compact and low-noise magnetometer for precise DC and low frequency magnetic field measurement. Yet, its output offset stability is insufficient for measurements in the environment with large temperature variations. In this research we have experimentally investigated the cause of the residual offset and its drift found in the bias-switched FM-OFG. Then we proposed a simple and effective method to drastically improve the sensor temperature characteristics of the FM-OFG in a practical feedback design with analog circuitry. Ideally, the induced voltages arisen by the uniaxial anisotropy of an amorphous wire core become symmetrical under flipped excitation polarities, and thus they are canceled by averaging. However, it was revealed that there was certain imbalance between them due to the asymmetry in wire’s magnetic properties, producing remnant component in the final output. The proposed method achieves equilibration of the imbalance component within the demodulation process of the induced voltages to minimize the residual offset and its drift in the final, averaged output. The method was verified by the experiment, and the offset stability of 0.013 nT/°C within the temperature range from −60°C to +70°C was achieved with good repeatability.

Mechanical Properties Test and Simulation Analysis of Glass Coated Amorphous Filaments

Taking the Co68.7Fe4Ni1B13Si11Mo2.3 glass-coated amorphous microwire as the research object, the mechanical properties of the amorphous wire were tested through biaxial tensile experiments, and the fracture deformation process of the amorphous wire was analyzed. Based on the experimental data, the finite element method was used The simulation software ABAQUS numerically simulates the tensile deformation of the amorphous wire, and the fracture relationship between the glass cladding layer and the core wire, and further reveals the tensile deformation fracture behavior of the amorphous wire was analyzed. The experimental results indicate that the fabricated microwires exhibit good tensile properties, and the maximum tensile breaking strength can reach 2918MPa; the fracture of the amorphous wire is a typical brittle fracture, and there is no obvious yield phenomenon. The tensile mechanics simulation results of the amorphous wire are consistent with the experimental results. The glass cladding layer breaks before the core wire, and the stress transfer effect in the amorphous wire is good. The model fracture is consistent with the fracture morphology of the amorphous wire. These results show that the amorphous wire exhibits good tensile properties and stress transmission capabilities, confirming the huge application potential of amorphous wire materials in sensor applications and functional composite materials.

Effect of welding conditions and flux compositions on the metallurgy of welded duplex stainless steel

This research tends to investigate the influence of shielded metal arc welding (SMAW) parameters and flux compositions on the metallurgy of welded AISI 2205 duplex stainless steel (DSS). The consumable was developed using the Al2O3-TiO2-SiO2 flux system as major flux ingredients. The spectrophotometer was used for determining the chemical composition of the base core wire and the base plate. The six different fluxes (F1, F2, F3, F4, F5 and F6, with varied compositions were coated on a 3.2 mm diameter of ER2209 core wire with a coating factor of 1.65 mm. Basicity indexes of the six formulated fluxes were calculated to be less than 0.9 for the developed electrodes, which confirmed the electrodes to be acidic coated electrodes. The influence of welding parameters, particularly current on the hardness characteristics of the weldment was established to ascertain the integrity and applicability of the developed consumable. It was evident that the average welding current of 120A at a constant voltage of 22.5 V produced high hardness properties of the welded joint of DSS with an optimal heat input of 1.65KJ/mm. The hardness properties in most sceneries were observed to be high at heat affected zone (HAZ) and fusion zone (FZ) than in the base metal (BM) region which is attributed to the ferrite content. The average hardness value of the BM was found to be 241Hv/20, for the FZ and HAZ using the produced electrode F5 and F6 were found to be 250HV/20 and 301HV/20 respectively and for F6 was found to be 259HV/20 at FZ and 336HV/20 at the HAZ while that of the commercial electrode (C) was found to be: FZ-245/HV/20 and HAZ-319/HV/20 which is a good indication of its conformity to standard DSS. The SEM-EDS morphological characterization also reveals the austenite-ferrite phase with relatively coarse grains, inter-critical grains and fine grains at the HAZ regions of the welded joint.

Microstructure and property of tungsten carbide particulate reinforced wear resistant coating by TIG cladding

WC particle-reinforced coating with high hardness and excellent wear resistance has been concerned extensively. In this paper, a method via powder core wire fed WC particle and TIG arc for manufacturing thicker WC particle-reinforced coatings was provided. The proportion of residual tungsten carbide particles in the coating and the degree of particle dissolution were worthy of attention. Energy per unit volume instead of line energy was used to represent heat input. By reducing the energy per unit volume, the proportion of residual tungsten carbide particles in the coating was increased while reducing the degree of dissolution of tungsten carbide particles. Besides, the crack resistance of the coating is also crucial. Ni and Nb elements were added to the core wire to improve the crack resistance of the coating. The dissolution behavior of tungsten carbide particles, phase composition, and the microstructure evolution of the coating was subsequently analyzed by SEM, EDS, and XRD. Finally, the hardness and wear resistance of the coating was tested, respectively.

Defect detection of Aluminum Conductor Composite Core (ACCC) wires based on semi-supervised anomaly detection

X-ray imaging is proven effective in the visualization of defects inside the Aluminum Conductor Composite Core (ACCC) wires. Although object detection pipelines have been extensively considered in the nondestructive testing tasks, the difficulty in obtaining defect samples has become the main obstacle to the application of such methods in the task of automatic defect detection for ACCC wires X-ray images. In this paper, we conducted a new semi-supervised approach based on anomaly detection. Different from the commonly used supervised methods, the proposed method requires only samples without defects for the learning process, therefore we are no longer limited by the insufficient and unbalanced defect samples. Experimental results show that the accuracy of the proposed method is up to 0.761, which proves the effectiveness of the method in the automatic defect detection of ACCC wires X-ray images.

Investigation of rapid composite plating of core wire magnetized electroplated diamond wire saw

In order to shorten the time for preparing diamond wire saws and improve the efficiency of preparing diamond wire saws, this study used nickel-plated diamond particles and magnetized stainless steel core wires. In order to effectively control the density of diamond particles, based on the analysis of the mechanism of the rapid composite coating of nickel-plated diamond and magnetic core wire magnetized diamond wire saw, it proposed a dynamic model suitable for computer simulation analysis. Using the simulation analysis model, the magnetic induction intensity of the core wire, the thickness of the nickel coating on the diamond surface, the stirring speed and the composite coating time on the effect of the composite coating of the diamond wire saw were systematically analyzed, and the reasonable parameters of rapid composite plating of the diamond wire saw was got, and verify the simulation results through experiments. Experiments show that the error range of the simulation calculation is 0.78% to 8.74%, and the simulation results can be a guidance in controlling the density of diamond particles. In addition, it was found in experiments that by using core wire magnetization and nickel plating on the diamond surface, the rapid composite plating efficiency was increased by over 66%; because of the shorter composite plating time, the diameter of the finished wire saw was smaller.

Hydrodynamic action in slicing PV polysilicon with a novel fixed and free abrasive combined wire sawing

This paper presents a novel fixed and free abrasive combined wire sawing which uses the diamond wire with surface abrasive-groups interval distribution and combines with free SiC abrasives slurry to obtain sliced surface that can be textured by acid etching. During the sawing process, the ability that the free abrasives lapping the sawn surface has a positive correlation with the elasto-hydrodynamic (EHD) pressure, and the appropriate size of the free abrasives is related to the minimum film thickness of the cutting coolant. In this paper, the EHD action during the FFACWS is analyzed, and the film thickness equation and Reynolds equation of the sawing area are deduced. The influences of feed speed, wire speed, wire tensioning force, cutting coolant viscosity, core wire diameter, and surface structure parameters on EHD pressure and film thickness are analyzed, which provides theoretical reference for selection of the free abrasives diameter and analysis of their lapping effect on the slice surface. The research results show that the EHD pressure changes periodically in the direction of the wire axis in the entire sawing area. The change period is the same as a structural change period of the abrasive area (AA) and the bare wire area (BWA) on the wire surface. In one period, there are two EHD pressure peaks. The size range of free abrasives should be greater than the protruding height of the fixed abrasives on the diamond wire and less than the minimum film thickness in BWA, so that the free abrasives can be constrained in BWA to lap the slice surface.

Effects of gas-assisted extrusion on slip in the cable coating process

Abstract The isothermal viscoelastic finite element method is used to simulate and analyze the process of cable coating extrusion, in which the Navier slip model is adopted. The Phan–Thien–Tanner differential viscoelastic constitutive equation is used to describe the flow characteristics of the polymer melt. The polymer material used for simulation is polypropylene. The extrudate swell, velocity field, pressure field and shear stress field are calculated by finite element method. The influences of the gas-assisted extrusion and traditional extrusion on wall slip of cable coating extrusion are compared. The results indicate that the extrudate swell ratio is the largest under the condition of the complete slip between core wire and melt during traditional extrusion process. The increase of core wire dragging velocity can lead to the increase of slip velocity, the decrease of pressure and the increase of shear stress of melt. Gas-assisted extrusion can eliminate the negative effects caused by the slip of core wire or the increase of core wire dragging velocity. Therefore, gas-assisted extrusion can reduce the energy consumption, improve the cable coating layer quality and increase the production efficiency during extrusion process.

CaO–CaF2–SiO2–Al2O3 system for development of SMAW electrodes with Ni alloy core wire

This research investigates the effect of CaO–CaF2–SiO2–Al2O3 based flux coating constituents of nickel-based electrodes on the weld chemistry of power plant applications. Extreme vertices design approach was used to prepare electrode coatings and extruded on FM-182 (Nickel based) core wire. TiO2 is added in a fixed amount to enhance the arc stability during welding and slag detachability. Weld beads were deposited on P22 alloy steel plate and examined for weld chemistry in terms of Cr, Ni, Nb and Fe. The microhardness of the deposited welds was also observed using Vicker's microhardness tester. Regression analysis was applied to develop a relationship between the weld chemistry and flux constituents. The results obtained from the regression analysis were then optimized to choose the best suitable electrode coating composition with higher desirability.

Experimental and numerical study on stress distribution in a cross section of Galfan spiral strand

The stress distribution law of the cross section of a Galfan spiral strand is studied in this paper. Axial tensile tests are carried out on four types of strands to obtain the relationship curve between the surface stress of the strand and the axial tension. The three-dimensional strand model is established by ABAQUS and verified by experiments. Based on the finite element model, the stress distribution in the cross section of a strand under different stress ratios is studied. The stress distribution coefficient is used to evaluate the degree of non-uniform stress distribution. The effects of wire diameter, wire lay length, and wire layer number on the distribution coefficient are then analyzed. The equation of the stress distribution coefficient of the core wire is obtained by regression, and the method for calculating the maximum stress of the strand is put forward.

SMART conductor on round core (CORC®) wire via integrated optical fibers

Superconducting cables based on high temperature superconductors (HTS) are necessary for applications requiring large currents and low inductance, such as compact fusion reactors. In this paper, we report the proof-of-concept of a SMART Conductor on Round Core (CORC®) wire realized via integration of optical fibers into the copper core. A SMART CORC® wire with integrated optical fibers was manufactured and its capabilities have been experimentally demonstrated. Results show that by interrogating the optical fibers via Rayleigh backscattering, a Spectral Shift signal as a function of time and position along the cable can be used to detect and locate hot-spots that are developed within the wire or its terminations. It has been found that highly localized current injection into the terminations could initiate hot-spots within the cable at locations where current redistribution between tapes occur. This effect is virtually eliminated when adequate current connections are used that inject current evenly along the cable terminations. Normal zone propagation velocities have been calculated as a function of time using Spectral Shift data for a heater-induced quench as well as a quench induced by overcurrent. In both cases the normal zone propagation velocity was about 6 cm s−1, but in the heater-induced experiment it was preceded by 500 ms of slower propagation at 2.5 cm s−1.

Fabrication of thin resin-bonded diamond wire and its application to ductile-mode wire sawing of mono-crystalline silicon

Fixed diamond wire has been the most common tool for slicing semiconductor ingots into wafers in fields of photovoltaics and integrated circuits. The diameter of diamond wire and thickness of wafers are decreasing dramatically to reduce material cost. Compared with electroplated diamond wire, resin-bonded diamond wire has a more uniform distribution of protrusion height, which leads to less crack damage, and therefore ensures further thinning of wafer thickness. However, due to the restriction of materials and resin-bonded diamond wire fabrication technology, the application of resin-bonded diamond wire is still limited. In this paper, thin resin-bonded diamond wire with core wire diameter of 60 μm is developed using a self-developed wire-fabricating device, and its corresponding morphology and sawing performance are evaluated. The examined quality of sawn wafers indicates that the thin resin-bonded diamond wire meets the requirement of wire sawing. Besides, a 3D morphology model for the thin wire is established considering the uniform distribution of protrusion height of abrasives. Wire sawing parameters to realize ductile-mode wire sawing of mono-crystalline silicon are determined using the established 3D morphology model.

Mechanical behavior and collapse mechanisms of innovative aluminum foam-based sandwich panels under three-point bending

Recent studies on innovative solutions in structural engineering fields highlight the effectiveness of closed-cell aluminum foams as traditional material/architecture core replacement in sandwich structures. This study aims to investigate the mechanical behavior and the collapse modes of innovative sandwich panels with aluminum foam as the core and stainless steel wire mesh-grid as the skins; the manufacturing process was based on the powder compact melting technique. The results of quasi-static three-point bending tests point out the beneficial effects, in terms of mechanical performance, of the reinforcement skin on the sandwiches, compared to the plain foams; this joins by their effectiveness in withstanding thermal and mechanical loads. Moreover, the investigation of the collapse mechanisms of the sandwiches with different thicknesses allows for testing the goodness-of-fit of the experimentally observed collapses with the ones predicted by the failure map from analytical models available in the literature.

Coil Optimization in a Fluxgate Magnetometer With Co₆₈.₂Fe₄.₃Si₁₂.₅B₁₅ Amorphous Wire Cores for Geomagnetic Station Observation

The coils in a three-axis fluxgate magnetometer have been investigated to enhance the noise and power performance for the use in geomagnetic stations. The turn number of the excitation and pickup coils in the fluxgate sensors is carefully optimized by measuring the equivalent magnetic noise spectral density of the magnetometers. Correspondingly, the values of the tuning and demodulation capacitors are delicately designed to match the optimized coils. The noise of the fluxgate magnetometer is 6 pT/ √Hz at 1 Hz with a power consumption lower than 360 mW. The size of the packaged magnetometer is 30 ×30 ×113 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> , and its weight is less than 80 g (without cable). The features of the fluxgate magnetometer make it a suitable instrument for geomagnetic stations and other applications.

New aspects on the performance of a fundamental mode orthogonal fluxgate magnetometer based on amorphous wire cores

The performance of a fundamental mode orthogonal fluxgate magnetometer based on Co68.15Fe4.35Si12.5B15 amorphous wires produced at National Inst. of R. &amp; D. for Technical Physics Iasi is presented. Our efforts are concentrated on reducing the sensor noise (magnetic noise + noise of the electronics) and at the same time on increasing the sensitivity in order to achieve a maximum signal to noise ratio. Making a parallel between conventional orthogonal fluxgate and fundamental mode orthogonal fluxgate operating principle, the differences in responsivity and noise have been explained based on magnetization mechanisms involved in the core.

A generalized simplified modeling method for electromagnetic coupling effects of uncertainty strapping cable harness

&lt;sec&gt;The cable harness provides a main gateway for electromagnetic interference(EMI) in electromechanical system. The unreasonable electromagnetic compatibility (EMC) design of cable harness will produce EMI to other on-board electronic equipment, bringing great safety risks to the system. Theoretical research and engineering practice indicate that most of the electromechanical systems cannot satisfy EMC standards, which can be attributed to the EMI generated by cables. As for the eletromagnetic(EM) illumination analysis, reliably and efficiently generating a full numerical model of cable harness is becoming more prominent for the EMC designers. Therefore, it is necessary to develop a more effective method to solve the modeling problem of cable harness. &lt;/sec&gt;&lt;sec&gt;In the practical application, the cable harness has the characteristics of spatial layout, and its characteristics such as “large number of core wires”, “arbitrary curvature of space” and “randomness of wiring” bring challenges to the modeling of EM coupling to cable harness. The numerical simulation of the whole cable harness model requires severe conditions for computational resource and even makes the EM coupling analysis impossible. Thus, considering the uncertainty of wire position, this paper proposes a generalized simplified modeling method for the EM coupling effect of uncertainty strapping cable harness. Firstly, the Gaussian distribution and spline interpolation are used to determine the location of the core conductors in the random bundling. Then, the distribution parameters of the cable harness at different positions are established by using the transposition relationship between the subsegments of the wires. Finally, the effectiveness of the proposed method is verified by numerical examples of the arc-shaped and sine-shaped harness. &lt;/sec&gt;&lt;sec&gt;In conclusion, this paper proposes a generalized simplification technique to model the EM illumination on cable harness with uncertainty wiring factors. By grouping the conductors together, the required computation time is markedly reduced and the complexity of modeling the completely cable harness is significantly simplified within a good accuracy. The proposed method provides a way of solving the modeling problem caused by “uncertainty strapping” of the complex wiring harnesses in electromechanical systems.&lt;/sec&gt;

The corrosion analysis and prevention of secondary cable joints used in outdoor terminal boxes of substation in humid environment

The reasons for corrosion cracking of secondary cable joints used in outdoor terminal boxes of a 220 kV substation in humid environment were investigated by scanning electron microscopy (SEM), X-ray diffractometer (XRD), infrared spectroscopy (IR) and ion dissolution test. According to the results of ion dissolution test, polyvinyl chlorid (PVC) insulated and sheathed cable material would precipitate chloride (Cl) ions under humid environment and at a certain temperature, which leads to accelerated corrosion cracking of the exposed copper core wires of secondary cable. In addition, the newly supplied PVC and cross-linked polyethylene (XLPE) materials without Cl precipitation under the same experimental conditions, indicating that PVC materials would precipitate Cl after reaching a service time threshold. Therefore, it is recommended that XLPE used for the insulation materials and accessories of secondary cable in outdoor terminal box of substation, as well as humidity in the terminal box should be controlled.

Development of an electrolyte jet type apparatus for manufacturing electroplated diamond wires

Multi-wire sawing with a fixed diamond wire is widely used for the mass production of wafers. In this study, a novel electrolyte jet type electroplating method was devised to improve the productivity of these wires. The method is based on increasing the limiting current density (LCD) in the electroplating unit. First, an electrolyte jet type electroplating unit was designed, and the plating characteristics were investigated. To increase the LCD during plating process, the method of decreasing the depletion layer of nickel ions around the core wire was approached. The experimental results indicated that the LCD can be increased by increasing the flow rate of the electrolyte. Next, the influences of composite plating conditions on the state of abrasive distribution and density of the diamond wires were experimentally verified, and the process of selecting the optimal fabricating conditions was clarified. Lastly, the cutting performance of the prototype diamond wires was verified by slicing a polycrystalline silicon ingot. The relationship between the surface roughness of the sliced wafers and the abrasive density of the diamond wires was studied.

Endüktans Seçim Kriteri ve Güç Elektroniği Uygulamaları için Tasarım Aşamaları

Güç elektroniği devreleri günümüzde yenilenebilir enerji uygulamaları ve enerji depolamak için kaçınılmaz aygıtlardır. Bu güç elektroniği devrelerinin ana elemanlarından biride endüktanstır. Endüktans bir canlının kalbi gibi çalışır, enerjiyi depolar ve çeviriciler de enerjiyi kaynaktan yüke doğru pompalar ve bu sayede yük devresine sürekli akım akışını sağlar. Bu yüzden iyi tasarlanmış bir endüktans çeviriciyi sürekli modda çalıştırmak için oldukça önemlidir ve böylece akım akışı kesintisiz olur. Bu çalışmada çeviriciyi sürekli modda çalıştırmak için gerekli bobin seçim kriteri literatürde incelenmiş ve sınır değer koşulu için kullanılan denklemler yardımıyla bulunmuştur. Yine gerekli denklemleri içeren tasarım aşamaları bir örnek uygulama ile gösterilmiştir. Çekirdek ve kabloların endüktans verimi üzerindeki etkisi de bu çalışmada incelenmiştir. Ferit çekirdek ve Litz teli kullanılan bir endüktans önerilmiş ve bir çevirici devresi için deneysel olarak tasarlanmıştır. Endüktans değerinin belirlenmesi için ölçümler gösterilmiştir. Ayrıca endüktans akım değişimleri yüksek frekanslar için araştırılmış, çeviricide kullanımı gösterilmiştir.

Finite element analysis of steel wire ropes considering creep and analysis of influencing factors of creep

In this study, a geometric model of a 7 × 19 steel wire rope with gaps between the wires is established by applying the Frenet frame used in the differential geometry theory. The positions of the point contacts between the wires and strands are determined. A 3-D beam element is used to model the steel wire in the wire rope. Moreover, the point contact element is used to simulate the friction and contact effect between the wires. A fine finite element model of the 7 × 19 steel wire rope is established in ANSYS. The creep constitutive model of the steel wire, which is a modified time-hardening model, is used to analyse the creep effect of the steel wire rope. The numerical simulation results are compared with the creep test data, and the accuracy of the numerical model is verified. Finally, various factors affecting the creep—including the friction between wires, gaps between wires and layers, twist angle of the core wire in a side strand, and that of the side wire in each strand—are analysed and discussed.