Electrode Diameter Research Articles

Optimization of process parameters for shielded metal arc welding for ASTM A 572 grade 50

The quality of a weld significantly depends on the mechanical characteristics of the welded joint, the welding process, and its associated input parameters. Insufficient parameter values can lead to welding defects and distortion that adversely affect mechanical properties. Consequently, carefully selecting appropriate parameters at an optimal level becomes crucial to mitigate defects, enhance productivity, and achieve desirable mechanical attributes in shielded metal arc welding (SMAW). This study explores optimizing SMAW parameters for ASTM A572 Grade 50 steel joints, vital in heavy machinery. Using Taguchi L16 array, parameters were varied across four levels. Grey relational and principal component analysis guided optimization. Results reveal groove angle's impact on tensile strength, electrode diameter on impact strength, and welding current on hardness and angular distortion. Optimal parameters were: 160 A welding current, 60° groove angle, 3.25 electrode diameter, 3 mm root gap, and 3 mm root face. Implementation of optimal parameters led to significant improvements: 10.53% higher tensile strength, 14.28% increased impact toughness, 8.55% reduced hardness, and a remarkable 33.33% decrease in angular distortion.

Review of MIG and TIG welding current variation of low-carbon steel materials based on tensile strength

SS400 and ASTM A36 a low-carbon steel materials that are used in the industry in the connection process to create materials according to the design. The aim of this research is to review the mechanical properties that occur in low-carbon steel materials in the MIG and TIG welding process with current variations and provide advice on low-carbon steel in welding. The materials used are ASTM A 36 and SS 304 steel. MIG welding uses a plate with a thickness of 6mm and uses AWS A5.18 ER 705-6 electrode diameter of 1.2mm. TIG welding uses a cylinder with a diameter of 6mm. The method of this review reported the tensile strength of low-carbon steel ASTM A36 with current variations of 150, 155, and 160A for MIG. Current variations of SS304 low-carbon steel are 80, 100, and 120A for TIG. The result of tensile strength with the MIG process produces the highest average current of 150 A of 354.92MPa. The results of tensile strength TIG process for 100A of 1007.31 MPa. The suggestion of this review is in MIG welding a greater current is required to obtain a high tensile strength value than the current required for TIG welding on low-carbon steel ASTM A 36 with a carbon content of 0.29% C and on SS304 with a carbon content of 0.042% - 0.07% C. Welding for stainless steel material can be used on TIG welding to get maximum tensile strength values. For ASTM A36 steel materials, MIG welding can be an option.

Considerations on the Electrode-Spacing-to-Electrode-Diameter Ratio in Electrical Resistivity Tomography (ERT): An Operational Approach

Considerations on the Electrode-Spacing-to-Electrode-Diameter Ratio in Electrical Resistivity Tomography (ERT): An Operational Approach

Parasitic Capacitance in High-Density Neural Electrode Arrays: Sources and Evaluation Methods.

This study aims to identify sources of parasitic capacitance in high-density neural electrode arrays and to provide an approach for evaluating their associated capacitance values. We also represent the effect of parasitic capacitance on the electrochemical properties of electrodes. Electrochemical impedance spectroscopy (EIS) and voltage transient (VT) measurements were employed to assess the parasitic capacitance of a 16-channel ultramicro-sized electrode array (UMEA) (8×25 μm2 electrode sites). The effect of parasitic capacitance on cyclic voltammetry (CV), EIS, and VT measurements of 20-μm diameter electrodes was assessed by comparing two different array designs: narrow and wide trace arrays. The capacitive leakage currents and charge during CV measurements were not significant, however, during current pulsing 34% underestimation of the maximum charge injection capacity corresponded to capacitive leakage. Capacitive leakage during EIS resulted in an underestimation of the electrode impedance at frequencies >1.5 kHz. The electrode design and insulation thickness can play a significant role in determining the amount of capacitive leakage during current pulsing and EIS at higher frequencies. Determining the sources and levels of capacitive leakage current in high-density neural electrode arrays, enables us to correct the measured value for the leakage current and thus estimate the electrode impedance and stimulation thresholds more accurately. This study highlights the importance of electrode design in developing high-density arrays with minimum capacitive leakage.

Multi-factors-regulated multi-level down-scalable and robust memristors

The memristor based on resistive switching (RS) behavior has attracted extensive attention due to its wide application prospects in artificial intelligence (AI) and information memory. In this work, a multi-factor responsive memristor based on Ag/MnO2/F-doped tin oxide (FTO) sandwich structure was fabricated by magnetic sputtering method. It was found that the RS behavior of the device was significantly improved when the diameter of the top electrode decreased from 2.0 mm to 0.5 mm, indicating that the device with Ag/MnO2/FTO structure has the down-scalable potential. Through comprehensive research, it can be concluded that the bipolar RS behavior of the memristor can be adjusted by multi-factors such as active layer thickness, top electrode size, voltage scanning rate, bias voltage amplitude and temperature. Specifically, the resistance-temperature dependence and temperature coefficient of the device in the low resistance state (LRS) indicate that the formation and disconnection of metallic Ag conductive filaments (CFs) play an important role in the RS behavior of the memristive device. Therefore, this work will lay an experimental and theoretical foundation for comprehensively understanding the mechanism of RS behavior and developing high-performance memristor with multi-level memory capacity.

Prediction of Impact Strength of TIG Welded Cr-Mo Steel Using Artificial Neural Networks

Welding is a critical and energy-intensive process with significant importance in the manufacturing industry, enabling the creation of joints capable of withstanding diverse loads without failure. Accurate prediction of welding parameters' effects on the thermal cycle and strength of metals during and after welding is essential to ensure the reliability of welds. This study investigates the influence of welding parameters such as welding current, material thickness, number of weld passes, and electrode diameter on the impact strength of Cr-Mo steel bars. Pure tungsten with 2% thoriated Tungsten Inert Gas (TIG) electrodes was used to join the metal sheets autogenously. Artificial neural network (ANN) was used in creating the model that predicts the impact strength of the steel. Sample with welding parameters of 15 mm thickness, 90 A current, 3 weld passes, and Ø2.4 mm electrode size exhibited the highest impact strength. Furthermore, the analysis of variance (ANOVA) results show that the material thickness and number of weld passes contribute significantly to the impact strength of the steel. The ANN model trained by the Levenberg-Marquardt algorithm had an average training dataset root mean square error (RSME) of 4.12%. This study contributes to the reliability and performance of welded joints in various applications.

Research on mechanism and experimental effect of tubular electrode dimensions on electric arc electrochemical composite machining

ABSTRACTThis research discusses the effect of typical characteristic dimensions of electrodes on electric arc electrochemical composite machining (EAECM). The flow rate and debris removal capability of electrodes with different characteristic dimensions were investigated by flow field simulation. Single-factor machining experiments were conducted. The discharge characteristics, process indicators and machined surfaces of electrodes were analyzed it was found that the tubular electrode has a demarcation phenomenon that affects the surface quality. The results indicate that the use of electrodes with large inner diameters is favorable to improve the surface consistency. The use of electrodes with small outer diameters improves the overall surface quality but increases the electrode wear. Finally, the fracture mechanism of thin-walled electrodes was revealed by stress field simulations and experiments. In conclusion, in order to improve the machining effect of EAECM, large-diameter (inner and outer diameter) electrodes with wall thickness greater than 2 mm should be selected.

Assessing Electrode Characteristics in Continuous Resistance Spot Welding of BH 340 Steel Based on Dynamic Resistance

The aim of this investigation is to offer a data-based scheme for predicting electrode wear in resistance spot welding. One of the major factors affecting the mechanical properties of spot welds and the variation in weld quality is electrode wear and alloying. In this study, Rogowski coils and twisted pairs attached to the top and bottom electrodes were used to obtain the welding current and the voltage between the electrodes in the welding process, thereby calculating the dynamic resistance value during the welding process. The electrode tip diameter was obtained from the pressure exerted by the upper and lower electrodes on the carbon paper when the current was cut off and was regarded as an indicator of electrode wear. By continuously welding 0.5 mm thick BH 340 steel plates until the electrode failed, the dynamic resistance signal was recorded in real time. Simultaneously, the electrode diameter after every several welds was also recorded. On this basis, the correlation between electrode tip diameter and dynamic resistance is studied. In order to quantitatively study the mapping relationship between dynamic resistance and electrode wear, 10 characteristic values were extracted from the dynamic resistance, and the stepwise regression method was used to obtain the regression formula between the characteristic values and the electrode tip diameter. Using new data to verify the effectiveness of the regression model, the acquired results display that the maximum error between the predicted value of the electrode tip diameter and the measured value obtained by the regression equation with the interactive quadratic term is 0.3 mm, and the corresponding relative error is 7.69%. When welding with a new pair of electrodes, the maximum absolute error was 0.72 mm, and the relative error of the model prediction is within 20% according to the linear regression model with interaction terms. This indicates that this regression model is barely satisfactory for monitoring electrode condition.

Hydrogen production through electrolysis and power generation through the fuel cell: an experimental and computational fluid dynamics study

The most prevalent element found in nature is hydrogen. It functions as fuel that could be used in cells or as automotive fuel when it is in the diatomic state rather than just a gas. There are many ways to produce hydrogen, and the current effort focuses on one of them: producing hydrogen using electrolysis. The present study aims to determine the influence of various parameters such as electrode length, electrode diameter, electrode material, electrolyte concentration, and volume of the electrolyzer. The amount of hydrogen produced by the various compositions has been contrasted. The hydrogen yield has been found to be increase with increases in the electrolyte concentration and electrode length, but it has been found to be decrease with increases in electrode diameter. The graphite electrode has produced higher yield than the stainless steel electrode. The hydrogen produced by the system had been utilized as a source for the fuel cell module in the simulation tests, and it showed that the hydrogen electrolysis integrated with the fuel cell module may be able to generate power.

Study on deformation theory and resonance frequency of circular-plane PVC actuator

The polyvinyl chloride (PVC) gel actuator has the advantages of low mass density, large actuation strain, good compliance, and simple fabrication. It deforms when excited by a voltage, and the deformation amplitude of the actuator is higher when an alternating current voltage of a specific frequency causes the actuator to resonate. In this paper, a circular-plane actuator based on PVC gel film and flexible electrodes was developed. Then, a theoretical model is established based on the Yeoh strain energy density function model and the mechanical analysis of deformation region-boundary constraints, the key parameters affecting the deformation are obtained. Subsequently, finite element simulation tests were done on the basis of this model, and the values of uniaxial stretching were highly consistent with the previous actual experimental results, which verified the reasonableness of the model and simulation method. Then, we focus on the analysis of the resonance frequencies of PVC actuators with different plasticizer content, electrode diameter, and pre-stretching degree. Finally, we compare the differences in time-domain characteristics of PVC actuators in the resonant and non-resonant states.

Differences in the Electric Field Distribution Predicted with a Mathematical Model of Cylindrical Electrodes of Finite Length vs. Infinite Length: A Comparison Based on Analytical Solution

Cylindrical-shaped metal electrodes are used in numerous medical specialties to force an electric field into the surrounding tissue (e.g., in electrical stimulation and electroporation). Although these electrodes have a limited length in reality, previous mathematical modeling studies have simplified the physical situation and have built a model geometry based on a cylindrical electrode of infinite length, which allows for reducing the model from 2D to 1D. Our objective was to quantify the differences in the electric field values between the finite and infinite electrode cases and assess the adequacy of the mentioned simplification for different values of electrode diameter and length. We used analytical solutions for the electric field distribution. We found that the electric field distribution is substantially different for both cases, not only near the edges of the electrode (when finite length is assumed) and in close locations (<1 mm), but even in the central area and at distances greater than 2 mm. Our work presents analytical solutions for both cases (finite and infinite length), which, despite the oscillations derived from computational limitations, could be used by researchers involved in electric field modeling in biological tissues, in order to quantify the possible error generated with simple models in geometric terms that assume infinite length.

Electric field distributions in realistic 3D rat head models during alternating electric field (AEF) therapy: a computational study

Objective. Application of alternating electrical fields (AEFs) in the kHz range is an established treatment modality for primary and recurrent glioblastoma. Preclinical studies would enable innovations in treatment monitoring and efficacy, which could then be translated to benefit patients. We present a practical translational process converting image-based data into 3D rat head models for AEF simulations and study its sensitivity to parameter choices. Approach. Five rat head models composed of up to 7 different tissue types were created, and relative permittivity and conductivity of individual tissues obtained from the literature were assigned. Finite element analysis was used to model the AEF strength and distribution in the models with different combinations of head tissues, a virtual tumor, and an electrode pair. Main results. The simulations allowed for a sensitivity analysis of the AEF distribution with respect to different tissue combinations and tissue parameter values. Significance. For a single pair of 5 mm diameter electrodes, an average AEF strength inside the tumor exceeded 1.5 V cm−1, expected to be sufficient for a relevant therapeutic outcome. This study illustrates a robust and flexible approach for simulating AEF in different tissue types, suitable for preclinical studies in rodents and translatable to clinical use.

Experimental Investigation of the Machining Characteristics in Graphite-Powder-Mixed Electrochemical Discharge Machining of Microholes in Glass.

The effect of graphite powder on the machining characteristics in graphite-powder-mixed electrochemical discharge machining of microholes was still not clear. How the discharge mechanism changed with the addition of graphite powder into the electrolyte, which further led to changes in the morphology of the machined holes, remained to be revealed. In this study, a series of microhole machining experiments were conducted in glass. Comparisons of the discharge energy, microhole entrance diameter, hole taper, and tool electrode morphology after machining were made when machining in the electrolytes with and without graphite powder. Experimental results revealed that there were a lot of small pulse currents distributed on the current waveform when machining with the graphite-powder-mixed electrolyte. The average discharge energy of the small pulse current was 2.8 times as much as that of the general electrochemical discharge. After introducing graphite powder into the electrolyte, the entrance diameter of the hole became larger when the hole depth was deeper than 200 μm. The HAZ width increased with increasing hole depth at the voltage of 37-41 V, while it decreased at the voltage of 43 V. A reduction in hole taper angle with a range of 0.5° to 2.3° was achieved. In addition, after machining in electrolytes with and without graphite powder, the tool electrode surfaces showed different morphologies due to different discharges.

Study of the Law Motion of the Micro-EDM Drilling Process

Micro-EDM is an unconventional technology used to machine every type of electrically conductive material regardless of its mechanical properties. Material removal occurs through electrical discharges between the workpiece and the electrode immersed in a dielectric fluid. In drilling operations, the technology is able to realise microholes with excellent quality in terms of precision, quality surface, roundness, and taper to the detriment of the machining time, which is less than other technologies. Several efforts are being made to improve different features related to the process performance that are severely affected by both the operative conditions, such as the electrode material or the type of dielectric, and process parameters. The typical indexes used to characterise the performance are the machining time, the material removal rate, and the geometric indexes. These indexes are very effective and are easily measurable, but they do not give information about the evolution of the drilling process, which could be irregular due to the different phenomena occurring during machining. The aim of this paper is the development of a method able to elaborate the motion law of the electrode during the micro-EDM drilling operation. In order to do this, a single hole was manufactured in several steps, recording both the machining time and electrode wear for each step. In this way, the actual position of the electrode during the drilling can be measured without the use of a predictive model for electrode wear. It was tested to confirm that the multistep procedure did not introduce new phenomena, in contrast to the traditional drilling operation. This method was used to study the effects of the electrode diameter, the type of electrode, the length of the electrode out of the spindle, and the entity of the run-out on the process performance. The tests were executed on titanium alloy sheets using a tungsten carbide electrode and hydrocarbon oil as the dielectric. It was found that the descent of the electrode into the workpiece was not regular, but it depended on the level of debris concentration in the machining zone. The debris concentration was influenced by the type and diameter of the electrode, its length out of the spindle, and, to a lesser extent, the run-out. This method was found to be a useful method for an in-depth analysis of the micro-EDM drilling process, contributing to a better understanding of the physical aspects of the process.

A method for grounding resistance calculation of vertical electrode

In this paper, a mathematical model on the grounding resistance of vertical electrode is proposed. The proposed mathematical model is modeled with consideration of the effects of parameters such as the length and diameter of vertical electrode, the soil resistivity and the embedding depth. This mathematical model can be applied effectively to the design of grounding system using vertical electrode in harmonious soil with the resistivity values less than 900Ω∙m. The accuracy of proposed model is proved by the simulation analysis and measurement examination of the electric field in this paper.

4D printing of shape-adaptive tactile sensor with tunable sensing characteristics

Using 4D printing to fabricate tactile sensors is promising, which will bring exciting functionalities to sensors, such as action self-sensing, environment self-adaptation, and self-healing. Here, we introduce 4D printing technology to fabricate the versatile smart tactile sensor with an adjustable measuring range and sensitivity, and shape adaptation for sensing in unstructured objects, which can sense touch from. The 4D-printed sensors (4DPS) with unique coplanar designs are achieved using a multi-material extrusion process for manufacturing interdigital electrodes composed of nanocarbon black/polylactic acid composites and shape memory polyurethane. The variability in the detection range and sensitivity stems from the changes in the electrode height and spacing caused by the deformation of shape memory polymer (SMP) under heat treatment. By setting printing parameters, not only can the diameter of the interdigital electrodes be precisely regulated, but 3D sensors that adapt to different curved surfaces can also be realized by utilizing thermal stress during the printing process. Moreover, the 4DPS is applicable to non-developable surfaces, such as spherical dome surfaces or saddle surfaces. Therefore, the shape-changing tactile sensor may offer great potential in environment self-adaptation and test range self-adjustment for human-robot cooperation in sensing.

Effect of collection efficiency and reducing ozone generation in an electrostatic precipitator with knife edge disk type electrode

In this study, the experiments were carried out to investigate the effect of a wire diameter on reducing ozone generation and improving the collection efficiency for particle sizes larger than 24 nm in an electrostatic precipitator (ESP) with wire electrode. Furthermore, the effect of the ESP with a knife-edge disk electrode was also investigated, since a wire will be broken. The ESP consisted of a discharging section and an electrostatic section. Two types of discharging sections were used. One was wire-to-plate configuration, and another was a knife-edge disk electrode structure. Positive DC high voltage was applied to the ESP, and gas velocity was 0.6 m/s. As a result, the collection efficiency increased as the diameter of the wire electrode decreased. The efficiency for particle sizes greater than 400 nm achieved more than 99.3%, and the average efficiency for the particle sizes between 24 nm and 213 nm was 99.8% at the ozone concentration of 0.01 ppm and the fine wire diameter of 0.1 mm. In the ESP with knife edge disk type electrode, the efficiency increased with decreasing the diameter of the disk electrode. The collection efficiency for particle sizes larger than 400 nm achieved 99.8% or higher, and the average efficiency for the sizes between 24 nm and 213 nm was 99.0% at the ozone concentration of 0.01 ppm and the disk diameter of 28 mm. The effect which was equivalent to the ESP with fine wire electrode was obtained in the ESP with knife edge disk electrode.

Exploiting Microelectrode Geometry for Comprehensive Detection of Individual Exocytosis Events at Single Cells.

Carbon fiber microelectrodes are commonly used for real-time monitoring of individual exocytosis events at single cells. Since the nature of an electrochemical signal is fundamentally governed by mass transport to the electrode surface, microelectrode geometry can be exploited to achieve precise and accurate measurements. Researchers traditionally pair amperometric measurements of exocytosis with a ∼10-μm diameter, disk microelectrode in an "artificial synapse" configuration to directly monitor individual release events from single cells. Exocytosis is triggered, and released molecules diffuse to the "post-synaptic" electrode for oxidation. This results in a series of distinct current spikes corresponding to individual exocytosis events. However, it remains unclear how much of the material escapes detection. In this work, the performance of 10- and 34-μm diameter carbon fiber disk microelectrodes was directly compared in monitoring exocytosis at single chromaffin cells. The 34-μm diameter electrode was more sensitive to catecholamines and enkephalins than its traditional, 10-μm diameter counterpart, and it more effectively covered the entire cell. As such, the larger sensor detected more exocytosis events overall, as well as a larger quantal size, suggesting that the traditional tools underestimate the above measurements. Both sensors reliably measured l-DOPA-evoked changes in quantal size, and both exhibited diffusional loss upon adjustment of cell-electrode spacing. Finite element simulations using COMSOL support the improved collection efficiency observed using the larger sensor. Overall, this work demonstrates how electrode geometry can be exploited for improved detection of exocytosis events by addressing diffusional loss─an often-overlooked source of inaccuracy in single-cell measurements.

Experimental investigation to optimize machining parameters for super duplex stainless steel in spark EDM using die-sinking and MQL system

The current experimental work discusses the electric discharge machining (EDM) of super duplex stainless steel with conventional die-sinking and minimum quantity lubrication (MQL) approach. The dielectric used in the conventional die-sinking EDM process is kerosene, and sunflower oil with air mixture is used in MQL-type machining conditions. The solid-type alpha brass electrodes of diameter 10 mm were used for machining. The most prominent input variables like pulse time (OFF and ON) and discharge current (varied at 3 levels) were selected, and Taguchi's L9 orthogonal array design was selected for experimentation. The responses like electrode wear rate (EWR), hole circularity (HC), material removal rate (MRR), and surface roughness (SR) were analyzed. The output results obtained from the experimental trials were analyzed using S/N ratios and analysis of variance (ANOVA). The most contributing input parameter affecting the responses like SR, HC, MRR, and EWR outputs were analyzed. The results showed that the optimum machining conditions were obtained at L3 and L9 levels for conventional die-sinking and MQL-type machining conditions, respectively. Out of three varying input parameters, pulse time (OFF) is the most contributing factor in deciding various responses. The same has been confirmed by ANOVA analysis. The theoretical prediction of experimental data was made using the Fuzzy logic approach, and the best optimal level is found out individually for all four responses.

Experimental study on streamer-leader transition characteristics of sphere-plane gap in valve hall under positive switching impulse voltage

Since a large number of spherical shielding balls are adopted in valve hall, investigating discharge characteristics of sphere-plane gap is of great significance for insulation design in HVDC projects. In order to study the discharge physical process of sphere-plane gap, this paper conducts sphere-plane gap experiment with gap distance set to 1.0 m and 1.5 m and electrode diameter set to 0.2 m, 0.3 m and 0.4 m under positive switching impulse voltage. The experimental comparative analysis of the discharge process of streamer-leader transition, and the physical parameters such as leader velocity and the amount of injected charge are calculated. The results show that the streamer to leader transition process is accelerated as the spherical electrode diameter increases. The leader velocity of sphere-plane gap is almost consistent with that of rod-plane gap. And the charge injected into initial streamer is much high than that of rod-plane gap.