Electrode Diameter Research Articles

INVESTIGATION ON ELECTRODE WEAR IN MICRO-EDM DRILLING

Micro-EDM drilling is extensively utilized in various industrial sectors due to its capability to machine all types of conductive materials, irrespective of their mechanical properties. This technology is particularly advantageous for drilling applications requiring high aspect ratios and precision. However, electrode wear, both frontal and radial, poses significant challenges, especially in blind hole drilling. This study proposes a mechanical method to measure electrode geometry through touch operations on a sharp target, varying the spindle rotation angle and Z depth. The method's effectiveness was validated through extensive experiments on Ti6Al4V plates using cylindrical and tubular electrodes of different diameters. The study varied energy types and tested new and steady-state electrodes. Results demonstrated the method's ability to detect changes in electrode tip shape under different conditions, revealing phenomena such as the correlation between electrode runout and wear, and the impact of internal washing on tip shape.

Resistive Switching Characteristics of NiO Thin Films Influenced by Changes in the Diameter of Nanometer-Scale Top Electrodes.

We investigated the forming, set, and reset voltages affected by the area of the top electrodes of a resistive random access memory (RRAM) capacitor fabricated by epitaxial NiO thin films. NiO RRAM capacitors with Au top electrode with a diameter of 100 μm showed typical unipolar switching characteristics. Au top electrodes with diameters of 10, 20, and 30 nm were formed on the surface of epitaxial NiO thin films by e-beam lithography. The forming, set, and reset voltages tended to decrease as the diameter of NiO RRAM capacitors with nanosized Au top electrodes decreased. As the area of the Au top electrodes increases, the volume of space in which the conductive filaments formed within the NiO RRAM capacitors can be formed becomes larger. This causes the conductive filament to be formed at relatively low energy, giving low forming voltages, while increasing the diversity of paths, causing a wide forming voltage distribution.

Electro-Discharge Machining of Microholes on 3d Printed Hastelloy Using The Novel Tool-Feeding Approach

Hastelloy, a nickel-based superalloy renowned for its exceptional resistance to corrosion at high temperatures, is widely used in sectors such as nuclear, aerospace, chemical processing, and pharmaceuticals. Microelectrical discharge machining (μ-EDM) is crucial for generating microholes and channels on Hastelloy. Since it effectively addresses difficulties like work hardening, high strength & wear resistance, and low thermal conductivity in traditional machining. Microholes play a major role in many critical components for precise control of fluids in fuel injectors, managing heat in turbine blades, controlled gas exchange, etc. The current research investigates the drilling of 8:1 aspect ratio microholes machined by 400μm diameter electrodes. This study investigated the influence of tool material (tungsten carbide, carbide drill bit, and brass) on μ-EDM performance. Compared to tungsten carbide and carbide drill bits, brass exhibited significantly lower electrode wear, leading to more precise microholes with reduced overcut and taper angle. However, brass also required a substantially longer machining time. Carbide drill bits offered a balance between wear resistance, machining time, and overcut/taper angle.

Revisiting the natural convection effects at ultra-low redox concentration solutions: The influence of viscosity and diameter of wire electrode

Natural convection could arise even at ultra-low redox concentration solutions (1–10 mM). Models such as convection–diffusion layer model and spontaneous convection model have been established to describe this phenomenon. However, the driving forces as well as the parameters that influence this natural convection effects are still not clear. Herein we investigated the effects of viscosity on natural convection by introducing sodium alginate (SA), which enhanced viscosity without changing the diffusion coefficient of the redox couple. Resultantly, it allowed us to obtain the relationship between microscopic flow of solutions and the thickness of natural convection layer. Moreover, wire electrodes with various diameters were also tested to reveal the natural convection effects on mass transfer. An empirical equation was established to describing the influences of solution viscosity and diameter of wire electrode on the thickness of natural convection layer in ultra-low redox concentration solutions.

Enhancing Ultrasonic Echo Response of AlN Thin Film Transducer Deposited by RF Magnetron Sputtering.

Accurate measurement of the pretightening stress for bolts has great significance for improving the assembly quality and safety, especially in severe environments. In this study, AlN thin film transducers were deposited on GH4169 nickel base alloy bolts using the RF magnetron sputtering, enabling a systematic investigation into the correlation between structures and the intensity of ultrasonic echo signals. Employing the finite element method resulted in consistency with the experimental data, enabling further exploration of the enhancement mechanism. With the increasing thickness of both the piezoelectric layer and the electrode layer, the intensity of the ultrasonic echo signals saw a great enhancement. The maximum-intensity observed increase is 14.7 times greater than that of the thinnest layers. Specifically, the thicker piezoelectric layer improves its mechanical displacement, while the increased thickness of the electrode layer contributes to better densification. An electrode diameter of nearly 4 mm is optimal for an AlN thin film transducer of M8 bolts. For pretightening the stress measurement, the sample with a strong and stable echo signal shows a low measurement error of pretightening below ±2.50%.

Consecutive diagnosis of nanosecond pulsed discharge in a coaxial electrode configuration using a quadruple emICCD camera system

Abstract Understanding the rapid dynamics of the primary streamer is crucial for comprehending the nanosecond pulsed discharge process. To reveal the fast primary streamer process, this study introduces a newly developed quadruple emICCD camera system capable of capturing a sequence of four discharge images in single pulse, coupled with self-customized software for data analysis. A nanosecond pulse power with its FWHM of 10.5 ns was applied to a coaxial reactor, focusing on the dynamics of the primary streamer. Our research clarifies the spatiotemporal variations of the primary streamer’s properties and examines their relation with inner electrode diameter (i.d. 0.2–2.0 mm). Results showed that in a pulse-powered coaxial electrode, there are three stages in the primary streamer process and that i.d. serves as an important factor influencing the formation and propagation of streamers. Interestingly, we found that streamer head velocity, streamer width, and streamer area for individual streamers remain constant prior to streamer channels reaching the outer electrode. Furthermore, we also observed an initial increase followed by a decrease in both streamer head velocity and streamer width with increasing i.d values. This study sheds light on the fundamental properties of the primary streamer during nanosecond pulsed discharge, contributing valuable insights for future plasma applications.

The effect of electric field uniformity on electrospun jet evolution and fiber morphology

Electric field distribution has a considerable impact on jet motion and resultant fibers’ diameter and morphology in electrospinning process. This study aims to explore the effect of electric field uniformity on jet evolution and fiber morphology by using auxiliary electrodes. Four disc auxiliary electrodes with different external diameters were designed. A high-speed photography equipment was employed to capture the jet motion. The morphology the fibers obtained from different locations of the jet were observed by the SEM to investigate jets evolution under different electric fields. The three-dimensional electric field were calculated by the ANSYS Maxwell software to simulate and quantify the electric field distribution throughout the electrospinning process. The results show that the larger diameter of the auxiliary electrode creates more uniform electric field distribution, smaller jet straight lengths, larger whipping amplitude, and lower the jet velocity. These factors result in finer and more uniform fibers. It was found that the morphology of fiber surface, beads shape and size also influenced by the uniformity of electric field distribution. This research indicates that a controllable uniform electric field was essential in preparing high-performance fibers.

Cost-effective fully 3D-printed on-drop electrochemical sensor based on carbon black/polylactic acid: a comparative study with screen-printed sensors in food analysis.

3D-printing technology allows scientist to fabricate easily electrochemical sensors. Until now, these sensors were designed employing a large amount of material, which increases the cost and decreases manufacturing throughput. In this work, a low-cost 3D-printed on-drop electrochemical sensor (3D-PES) was fully manufactured by fused filament fabrication, minimizing the number of printing layers. Carbon black/polylactic acid filament was employed, and the design and several printing parameters were optimized to yield the maximum electroanalytical performance using the minimal amount ofmaterial. Print speed and extrusion width showed a critical influence on the electroanalytical performance of 3D-PES. Under optimized conditions, the fabrication procedure offered excellent reproducibility (RSD 1.3% in working electrode diameter), speed (< 3min/unit), and costs (< 0.01 $ in materialcost). The 3D-PES was successfully applied to the determination of phloridzin in apple juice. The analytical performance of 3D-PES was compared with an equivalent commercial on-drop screen-printed electrode, yielding similar precision and accuracy but lower sensitivity. However, 3D-PES provides interesting features such as recyclability, biodegradability, low-cost, and the possibility of being manufactured near the point of need, some of which meets several demands of Green Chemistry. This cost-effective printing approach is a green and promising alternative for manufacturing disposable and portable electroanalytical devices, opening new possibilities not only in on-site food analysis but also in point-of-care testing.

Influence of submerged arc welding process parameters and metallurgical behaviour in a thick carbon steel section for boiler application

AbstractThe aim of the research is to investigate the weldability of thick sections of carbon steel using submerged arc welding with varying process parameters. The experimental design for joining thick carbon steel involves manipulating input weld process parameters such as current (A), voltage (V), weld speed (mm/h), and weld electrode diameter (mm). The quality of the weld material is assessed based on transformations in microstructure, weld hardness measured by Brinell hardness number, and tensile strength (MPa). It is crucial to note that the grain structure and metallurgical behavior of other hard materials may differ significantly. The presence of carbon in the ferrite phase has led to the formation of bainite, martensite, and composites of martensite and austenite within the weld zone, as confirmed by high‐resolution microscopy. The weldment‘s hardness has increased from 242.5 HV 30 in the base metal to 316.4 HV 30 in the weldment due to metallurgical alterations in the microstructure. Weld energy input emerges as the primary factor influencing weld quality. With increasing weld current and voltage, there is a corresponding increase in the joined metal, resulting in improved characteristics in the weld structure, particularly at maximal energy input and welding speed. In the context of boiler applications, understanding the weldability of thick carbon steel sections is paramount for ensuring structural integrity and longevity under high‐temperature and high‐pressure conditions. The optimized welding parameters identified in this study can contribute to enhancing the reliability and performance of boilers, thereby promoting safety and efficiency in industrial settings.

Performance optimization of an air-assisted electrostatic spraying unit using response surface methodology

An air-assisted electrostatic spraying unit along with a set-up to measure the spray current was developed. Response surface methodology was used to optimize the performance of the developed electrostatic spraying unit. The optimum parameters such as electrode diameter, electrode voltage, electrode position and target distance for maximizing charge-to-mass ratio (CMR) were determined to be 30 mm, 2000 V, 0 mm and 400 mm, respectively Predicted CMR under optimal conditions was experimentally validated. Furthermore, charged spray demonstrated 1.5 to 4.6 times higher droplet deposition with lower uniformity coefficient (2.13–2.14) and relative span factor (0.84–0.9) compared to uncharged spray.

Numerical analysis of electrohydrodynamic printing under electric field focusing mode

As an emerging micro/nanoscale 3D printing technology, Electrohydrodynamic (EHD) printing has undergone rapid development in recent years. However, in most EHD printing processes, voltage is directly applied to both the nozzle and the substrate, resulting in the electric field being influenced by the printing height. This poses challenges for printing three-dimensional curved surface structures. This study presents a comprehensive investigation into the EHD jetting process, utilizing a novel voltage loading method that separates electrodes from both the nozzle and the substrate. Through experimental setups and numerical simulations, this research was conducted to examine the effects of printing height, voltage, and electrode diameter on jetting behavior. The results show that compared to the traditional electrode form, the new voltage loading method will increase the electric field intensity of the liquid surface before ejection by 37.1% and is more conducive to the formation of Taylor cones. It can ensure that the printing fluctuation is less than 2.4% when the printing height varies between 1.5–2.5 times the nozzle diameter, which is more favorable for printing multi-layer structures. The threshold voltage for ejection is provided in this model. When the electrode is reduced, the efficiency of electric field utilization will be further improved, but the acceleration of the jet velocity will cause an increase in droplet size. The findings highlight the method’s capability to maintain consistent droplet sizes and electric field intensities across varying conditions, thereby enhancing printing stability and efficiency. The study’s innovations provide valuable insights for advancing micro/nano 3D printing technologies, emphasizing the potential for improved EHD printing processes in practical engineering applications.

Investigating micro drilling with electrical discharge machining on nickel-based superalloy: effects of electrode material and diameter

Investigating micro drilling with electrical discharge machining on nickel-based superalloy: effects of electrode material and diameter

Sensitivity and Validation of Porous Membrane Electrical Cell Substrate Impedance Spectroscopy (PM-ECIS) for Measuring Endothelial Barrier Properties.

Measurement of endothelial and epithelial barrier integrity is important for a variety of in vitro models, including Transwell assays, cocultures, and organ-on-chip platforms. Barrier resistance is typically measured by trans-endothelial electrical resistance (TEER), but TEER is invasive and cannot accurately measure isolated monolayer resistance in coculture or most organ-on-chip devices. These limitations are addressed by porous membrane electrical cell-substrate impedance sensing (PM-ECIS), which measures barrier integrity in cell monolayers grown directly on permeable membranes patterned with electrodes. Here, we advanced the design and utility of PM-ECIS by investigating its sensitivity to working electrode size and correlation with TEER. Gold electrodes were fabricated on porous membrane inserts using hot embossing and UV lithography, with working electrode diameters of 250, 500, and 750 μm within the same insert. Sensitivity to resistance changes (4 kHz) during endothelial barrier formation was inversely proportional to electrode size, with the smallest being the most sensitive (p < 0.001). Similarly, smaller electrodes were most sensitive to changes in impedance (40 kHz) corresponding to cell spreading and proliferation (p < 0.001). Barrier disruption with both EGTA and thrombin was detectable by all electrode sizes. Resistances measured by PM-ECIS vs TEER for sodium chloride solutions were positively and significantly correlated for all electrode sizes (r > 0.9; p < 0.0001), but only with 750 μm electrodes for endothelial monolayers (r = 0.71; p = 0.058). These data inform the design and selection of PM-ECIS electrodes for specific applications and support PM-ECIS as a promising alternative to conventional TEER for direct, noninvasive, real-time assessment of cells cultured on porous membranes in conventional and organ-on-chip barrier models.

·OH Scavenger Optimized Grounding Electrode Atomization Corona Discharge Technology for Treatment of Coal Mine Acidic Wastewater

Coal mine acid drainage is a type of industrial wastewater generated in the process of coal production and utilization that has a low pH and contains a small amount of organic matter and SO42−, which is harmful to the environment. The ·OH scavenger was used to optimize the grounded electrode atomized corona discharge (GEACD) technology for the treatment of coal mine acidic wastewater. The effects of various factors on the discharge effect were investigated, and the optimal operating scheme for the subsequent test was determined as 35 mm distance between barrel electrodes, 0.6 mm diameter of wire electrodes, and a flow rate of 45 mL/min. The effects of discharge voltage, discharge time, and ·OH scavenger on COD removal rate and pH in coal mine acid drainage were also investigated. The results showed that at the optimum discharge voltage of 12 kV, discharge time of 66 min, and SO42− to ethanol concentration ratio of 1, the COD value decreased from 152.84 mg/L to 43.27 mg/L, and the pH value increased from 5.6 to 6.1.

PERFORMANCE ENHANCEMENT OF BRASS EDM ELECTRODES WITH CRYOGENIC TREATMENT WHILE MACHINING THE COLD WORK STEEL AISI D2

This study investigates the performance of deep cryogenically treated brass (CuZn25Al5) electrodes in the die-sink EDM process. Two different cryogenic treatment durations, 6 h and 12 h, were applied to 8 mm diameter electrodes, and their effects were compared to untreated electrodes. The machining tests were conducted under moderate and aggressive conditions. In the machining tests, the 6-h cryo-treated electrode exhibited a 16.8% increase in material removal rate (MRR) under moderate conditions and a 19.7% increase under aggressive conditions compared to the reference electrode. The 12-h cryo-treated electrode showed similar MRR values to the reference electrode but improved tool wear resistance by 9.4% under moderate conditions. The kerf angle was minimized, indicating better hole verticality, in the 6-h cryo-treated electrode group. The improvement in machining performance was attributed to the enhancement in electrical conductivity of the electrodes, which increased by 28% for the 6-h cryo-treated electrode and 20% for the 12-h cryo-treated electrode. X-ray diffraction (XRD) analysis revealed shifts in peak positions and possible phase transformations due to cryogenic treatment. Surface roughness measurements showed improved surface conditions in the cryo-treated electrodes under aggressive conditions. The results indicate that cryogenic treatment enhances MRR, reduces tool wear, and improves surface quality in die-sink EDM. These improvements are attributed to increased electrical conductivity and changes in the internal structure of the brass electrode.

Numerical analysis and structural optimization of a DLC coated capacitance wire-mesh sensor for measuring liquid metal-gas two-phase distribution

The detection of liquid metal-gas two-phase distribution in lead-cooled fast reactor once steam generator tube rupture occurs is vital to the security assessment of the reactor core. In this paper, considering the high temperature, corrosiveness and high conductivity of the liquid metal, a diamond-like carbon coated capacitance wire-mesh sensor is proposed to detect the two-phase distribution in liquid metal. Based on the software COMSOL, a numerical model is firstly established that is quantificationally verified by experiment to study and optimize the performance of the coated WMS. The measurement accuracy of the sensor is investigated by ranging the AC excitation frequency and structure parameters of the system. The results show that the liquid metal has blocking effect on the small bubbles and the sensor has great measurement accuracy when the transverse and vertical interval are 2 mm while the exitation frequecy, coat thickness and electrode diameter show little effect. This research could guide the measurement in liquid metal-gas two-phase flow.

Impact of glioma peritumoral edema, tumor size, and tumor location on alternating electric fields (AEF) therapy in realistic 3D rat glioma models: a computational study

Objective. Alternating electric fields (AEF) therapy is a treatment modality for patients with glioblastoma. Tumor characteristics such as size, location, and extent of peritumoral edema may affect the AEF strength and distribution. We evaluated the sensitivity of the AEFs in a realistic 3D rat glioma model with respect to these properties. Approach. The electric properties of the peritumoral edema were varied based on calculated and literature-reported values. Models with different tumor composition, size, and location were created. The resulting AEFs were evaluated in 3D rat glioma models. Main results. In all cases, a pair of 5 mm diameter electrodes induced an average field strength >1 V cm−1. The simulation results showed that a negative relationship between edema conductivity and field strength was found. As the tumor core size was increased, the average field strength increased while the fraction of the shell achieving >1.5 V cm−1 decreased. Increasing peritumoral edema thickness decreased the shell's mean field strength. Compared to rostrally/caudally, shifting the tumor location laterally/medially and ventrally (with respect to the electrodes) caused higher deviation in field strength. Significance. This study identifies tumor properties that are key drivers influencing AEF strength and distribution. The findings might be potential preclinical implications.

MULTIFACTOR ANALYSIS OF THE EFFICIENCY OF THE FERROALLOY PROCESS

Ore-reducing ferroalloy processes must be considered as a relationship of parameters and characteristics of subsystems and elements. The maximum energy capacity of the furnace and its productivity is achieved both due to the design parameters of the bath, the short network, the power of the furnace transformer, the diameter of the self-ignition electrodes, as well as the electrotechnological and thermophysical properties of the initial charge materials, ore-slag melt and final ferroalloy. The amount of carbon is one of the most significant technological parameters of the carbon reduction process for the production of manganese ferroalloys. In the work, the most significant final indicators are adopted and their correlation with electrical characteristics and technological parameters is determined.

Mapping of the central sulcus using non-invasive ultra-high-density brain recordings

Brain mapping is vital in understanding the brain’s functional organization. Electroencephalography (EEG) is one of the most widely used brain mapping approaches, primarily because it is non-invasive, inexpensive, straightforward, and effective. Increasing the electrode density in EEG systems provides more neural information and can thereby enable more detailed and nuanced mapping procedures. Here, we show that the central sulcus can be clearly delineated using a novel ultra-high-density EEG system (uHD EEG) and somatosensory evoked potentials (SSEPs). This uHD EEG records from 256 channels with an inter-electrode distance of 8.6 mm and an electrode diameter of 5.9 mm. Reconstructed head models were generated from T1-weighted MRI scans, and electrode positions were co-registered to these models to create topographical plots of brain activity. EEG data were first analyzed with peak detection methods and then classified using unsupervised spectral clustering. Our topography plots of the spatial distribution from the SSEPs clearly delineate a division between channels above the somatosensory and motor cortex, thereby localizing the central sulcus. Individual EEG channels could be correctly classified as anterior or posterior to the central sulcus with 95.2% accuracy, which is comparable to accuracies from invasive intracranial recordings. Our findings demonstrate that uHD EEG can resolve the electrophysiological signatures of functional representation in the brain at a level previously only seen from surgically implanted electrodes. This novel approach could benefit numerous applications, including research, neurosurgical mapping, clinical monitoring, detection of conscious function, brain–computer interfacing (BCI), rehabilitation, and mental health.

Enhancing TIG Welding Parameters For Direct Tensile Load (DT-load) On Various Steel Thicknesses

The car body repair process is integral to vehicle development and structural repair. The primary objective of this study is to enhance the quality of thin material welding utilized in automobile body repair. The impetus for this research stems from the necessity to improve the structural integrity and longevity of thin materials prone to deformation throughout the welding procedure while minimizing distortion. This study aims to identify optimal parameters for the tungsten inert gas welding (TIG welding) process on thin materials, particularly for automobile body rearrangement. The Taguchi method conducted the experimental analysis of variations in welding parameters, including electrode diameter, gas flow rate, and welding current. Adjusting TIG welding parameters to their optimal values significantly improves weld joint direct tensile load (DT-load) and overall structural quality, according to the findings of this study. ANOVA analysis and the S-N ratio indicate that gas flow rate and welding current are significant determinants of the quality of welded joints in thin materials. This research contributes to a better understanding of the optimal parameters for fusing thin materials, particularly in automobile body repair. The automotive industry can use these findings as a guide to enhance the quality and strength of welding processes, which are critical to the structural integrity of vehicles.