Electrical Process Parameters Research Articles

Phenol-formaldehyde resin enriched with graphene nanoplatelets as an electroconductive adhesive for wood composites

The study demonstrates that phenol-formaldehyde (PF) resin, commonly used for lignocellulosic composites, can become electroconductive when modified with graphene nanoplatelets (GNPs) while still serving as an effective adhesive for particleboard production. The PF resins enriched with various amounts of GNPs were tested for viscosity, gel time, and thermal stability, followed by electrical conductivity measurements for GNP-enriched resins applied to several lignocellulosic surfaces of varying wettability. These tests showed that the optimum weight percentages of GNP at which the resins maintain both the electrical conductivity and process parameters, enabling the formation of particleboard, amount to 18.5%. Consequently, a prototype of electroconductive particleboard was created and evaluated for bending strength (EN 310: 1993), modulus of elasticity (EN 310: 1993), tensile strength (EN 319: 1993), thickness swelling (EN 317: 1993), water adsorption (PN-76/D-04234) and formaldehyde emission (EN ISO 12460–5:2015). Impressively, the panels achieved a conductivity of 320 Ω m, indicating their potential use as resistive heaters and other applications in the Internet of Things (IoT) area. Simultaneously, the GNP-enriched panels showed formaldehyde emission well below the threshold set by the standards and exhibited mechanical properties that in most cases met the criteria for use in furniture and interior design.

Numerical simulation of oil shale in-situ exploration productivity comparison between steam injection and electrical heating

Oil shale is an important alternative resource to the conventional oil and gas because of its rich reserves. The in-situ heating exploitation is the most promising method to produce oil from the oil shale, mainly including electrical heating and steam injection heating. However, to the best of our knowledge, a comprehensive comparison between these two kinds of heating methods is still absent, thus the comparison is necessarily conducted to provide suggestions on how to select heating modes for the oil shale in-situ exploitation. On this basis, a systematic comparison is presented between in-situ steam heating and electrical heating, including physical and process parameters, and then sensitivity analysis and optimization on key parameters are carried out. Simulation results show that steam injection heating is superior to electrical heating in output, energy consumption and production cycle. The flow rate and temperature of the injected steam and the specific heat capacity of oil shale are sensitive to productivity. The production will be increased with larger injection flow rate and temperature. The thermal conductivity and porosity are less sensitive to the mining efficiency compared to the injection flow rate and temperature. At the same time, different well pattern structures also have an impact on productivity, and the hexagonal well pattern has better productivity benefits than the triangular and quadrilateral well patterns. In the simulation case of this paper, the most conducive parameters for exploitation were derived as injection flow rate 0.20 kg/s, injection temperature 650 °C, specific heat capacity 1.5 kJ/(kg⋅K), thermal conductivity 0.5 W/(m⋅K), porosity 0.05. These results are expected to provide theoretical suggestions for improving the productivity efficiency of oil shale in-situ exploitation.

EFFECT OF PROCESS PARAMETERS ON THE PERFORMANCE OF POWDER MIXED EDM OF Ni-BASED SUPERALLOYS: A REVIEW

Ni-based superalloys fall under the category of difficulty in machining type material owing to their poor thermal conductivity and high strength at extreme temperatures. Machining such materials using the traditional approach is a tremendously difficult task. On the other hand, EDM, one of the most sophisticated electro-thermal manufacturing processes, is used to machine such materials. It is a well-known non-traditional machining process for generating parts that require accuracy, have complex shapes, and are small in size. However, the use of EDM in Ni-based superalloys has some disadvantages like poor surface finish and low material removal rate. So, to alleviate these disadvantages, researchers introduced powder mixed dielectric fluid in the EDM process. Further, the performance of this technique has been enhanced by studying the effect of various nano/micro-size particles and their concentrations in the dielectric medium. In this paper, the authors have reviewed the impact of non-electrical and electrical process parameters on the output responses when machining Ni-based superalloys using powder mixed EDM. The challenges faced during the conventional machining of Ni-based superalloys and the mechanism proposed for powder mixed EDM, especially under the influence of suspended powders into the dielectric medium have also been presented in this paper. Finally, future research areas of powder mixed EDM of Ni-based Superalloys, such as (i) its modelling and simulation and (ii) the effect of tool motion and powder properties on its performance, are discussed in brief.

Influence of the parameters of the impact of electrical impulses on the yield of juice from the pulp

This article presents the results of experimental studies to determine the effect of electrical impulse processing parameters on the output of juice from the pulp. It is based on the effect of pulse energy and voltage on apple juice. The influence of an electrical impulse on the production of juice before pressing fruit pulps has been studied. It is based on the optimal parameters of the grinding rate of the raw material, which affects the efficiency of processing with electric pulses. An additional large amount of juice was detected after the pulp was treated with electrical impulses. Based on the voltage dependence of the juice obtained from the raw material and the direct interaction of the field with the electrically charged system of the cell protoplasm.

Influence of electrical process parameters to inactivate microorganisms in orange juice by PEF technology

Pulsed electric field (PEF) is a non-thermal/chemical food processing method for microbial inactivation in liquid food. This method finds its application to prolong the shelf-life of the seasonal fruit juices which helps to maintain the supply chain throughout the year. So, in the present study, the most commonly found microorganisms of Escherichia coli (E. coli), Staphylococcus aureus (S.aureus) and Saccharomyces cerevisiae (S.cerevisiae) inoculated in orange juice are considered. PEF impact on microbial inactivation based on the experimental results are analyzed with respect to pulse frequency, electric field intensity and treatment time. The PEF treatment conditions set for the investigation are as follows. Electric field intensity: - 5 kV/cm and 10 kV/cm; Pulse frequency: - 1, 10, 20 and 50 kHz; Pulse width: - 1.2 µs; Treatment time: - 10 s, 20 s, 30 s, 40s and 50s. A maximum inactivation of log10 reduction 2.62 ± 0.122 is observed when E. coli was subjected to 10 kV/cm at 50 kHz. Meanwhile S.cerevisiae and S.aureus are inactivated at the level of log10 reduction 2.4 + 0.16 and 2.1 + 0.9 respectively at the same treatment conditions when the treatment time is 50 s. It is also observed that the electric field intensity along the higher frequency enhances the inactivation level of microorganisms and the variations in the log reduction might be due to the different biological structure of the microorganisms.

Dissolution Behavior of Different Alumina Phases within Plasma Electrolytic Oxidation Coatings

The influence of chemical redissolution in the PEO layer-growth equilibrium on aluminum is evaluated differently in literature. In order to estimate whether and to what extent various alumina modifications could be affected by redissolution processes during PEO, immersion experiments were carried out on PEO coatings in model electrolytes of different alkalinity and silicate concentration. Their composition was determined spectroscopically before and after the experiments. The layers were characterized by XRD before and after the tests and examined at affected and unaffected zones using SEM, EDX, and EBSD. The results show that chemical oxide dissolution can only be observed at the layer/substrate interface and that primarily amorphous alumina is affected. This process is intensified by higher alkalinity and inhibited by silicate additives. The crystalline Al2O3 modifications show no significant attack by the electrolytes used. Transferring these observations to plasma electrolytic oxidation, they allow the conclusion that the electrochemically active zone in the pore ground of discharge channels interacts with the electrolytic and electrical process parameters throughout the entire PEO procedure. Influences of bath alkalinity and silicate content on layer growth rates are to be understood as impact on the passivation processes at the layer/substrate interface rather than chemical redissolution.

Multilayer Conductive Metallization With Offset Vias Using Aerosol Jet Technology

Abstract The transition of additive printed electronics into high-volume production requires process consistency to allow quality control of the manufactured product. Process recipes are needed for multilayer substrates with z-axis interconnects in order to enable complex systems. In this paper, process recipes have been developed through fundamental studies of the interactions between the process parameters and the mechanical–electrical performance achieved for multilayer substrates. The study reported in this paper focuses on printed vias also known as donut vias. Aerosol jet process parameters studied include carrier mass flow rate, sheath mass flow rate, exhaust mass flow rate, print speed, number of passes, sintering time and temperature, UV-intensity for UV-cure, and standoff height. The electrical performance has been quantified through the measurements of resistance. The mechanical performance has been quantified through measurement of shear load-to-failure. The effect of sequential build-up on the mechanical–electrical properties vs process parameters has been quantified for up to eight-layers designs. The performance of five-layer and eight-layer additively printed substrate designs and effect of multiple vias has been compared to assess process consistency.

Optimization of electrical process parameters of WEDM on ECAP Al7075 alloys considering Radial Overcut (ROC) as output response

The aim and objective of the present experimental work is to find out the predicted value of Radial overcut (ROC) while processing of Al7075 alloy through Equal Channel Angular Pressing (ECAP) with channel angel 90 degree and edge angle 20 degree with chosen process route C and alongwith suitable back pressure and subsequently machining that ECAP sample by Wire cut electric discharge machining (WEDM). Response Surface Methodology is applied in present study to predict the ROC in WEDM process for previously ECAP Al7075 alloy. Pulse off time (Toff), pulse on time (Ton), peak current (IP) and servo voltage (SV) are taken as input electrical parameters of process to study the ROC. The experiment was designed to perform based on Central Composite Design (CCD) method. After performing 31 experimental runs a mathematical model was being evolved for finding out the correlation and significance of electrical parameters on ROC. The coefficients were obtained by performing analysis through ANOVA at 95% confidence level.Observation shows that Ton and IP has got significant impact on ROC. The forecasted results based on mathematical model generated are found to be in a reasonably good degree of accuracy with the experimental result. Optimum value of radial overcut is obtained experimentally as 26.075 µm against Ton 7 µs, Toff 54 µs, for IP value 100 A and SV 25 V respectively.

Sustainability and recent trends in micro- electric discharge machining (μ-EDM): A state-of-the-art review

In the era of miniature machining, micro Electrical -discharge machining (A thermal energy based materials removal process) is the most recognized non- conventional machining approaches which has the ability to generate complex 2D & 3D shapes on difficult to machine materials in a short time while maintaining high feature quality. Micro-EDM is a noncontact machining process that produces mould cavity and deep holes with less metallurgical losses, stress free and miniaturized features through careful regulation of the electrical and non-electrical process parameters. Input parameters such as current, voltage, and pulse on time, pulse off time and Duty factor play an imperative role to achieve good feature quality. This progressive review of micro–electrical discharge machining studies latest machinable composite materials (conductive), dielectric fluids, issues of surface integrity and various optimization techniques with the perspective of sustainability (i.e. high energy consumption, electrode wear, generation of hazardous dielectric waste, toxic emissions and fire hazard). A brief note on future research trends has been included in the last section. Moreover, recent applications and advantages of micro-EDM machining processes are also presented in this study.

Indoor air quality improvement and purification by atmospheric pressure Non-Thermal Plasma (NTP)

Non-thermal plasma (NTP) is a promising technology for the improvement of indoor air quality (IAQ) by removing volatile organic compounds (VOCs) through advanced oxidation process (AOP). In this paper, authors developed a laboratory scale dielectric barrier discharge (DBD) reactor which generates atmospheric NTP to study the removal of low-concentration formaldehyde (HCHO), a typical indoor air VOC in the built environment associated with cancer and leukemia, under different processing conditions. Strong ionization NTP was generated between the DBD electrodes by a pulse power zero-voltage switching flyback transformer (ZVS-FBT), which caused ionization of air molecules leading to active species formation to convert HCHO into carbon dioxide (CO2) and water vapor (H2O). The impact of key electrical and physical processing parameters i.e. discharge power (P), initial concentration (Cin), flow rate (F), and relative humidity (RH) which affect the formaldehyde removal efficiency (ɳ) were studied to determine optimum conditions. Results show that, the correlation coefficient (R2) of removal efficiency dependence on the processing parameters follow the order R2 (F) = 0.99 > R2 (RH) = 0.96, > R2 (Cin) = 0.94 > R2 (P) = 0.93. The removal efficiency reached 99% under the optimum conditions of P = 0.6 W, Cin = 0.1 ppm, F = 0.2 m3/h, and RH = 65% with no secondary pollution. The study provided a theoretical and experimental basis for the application of DBD plasma for air purification in the built environment.

Exploiting ferroelectric and ferroelastic effects in piezoelectric energy harvesting: theoretical studies and parameter optimization

While piezoelectric energy harvesting typically focuses on converting mechanical into electrical energy on the basis of the linear reversible piezoelectric effect, the potential of exploiting the non-linear ferroelectric effect is investigated theoretically in this paper. Due to its dissipative nature, domain switching, on the one hand, is basically avoided in order to prevent mechanical energy from being converted into heat. However, the electrical output, on the other hand, is augmented due to the increased change of electric displacement. In view of these conflicting issues, one main objective in ferroelectric energy harvesting thus is to identify mechanical and electrical process parameters providing appropriate figures of merit. Being an efficient approach to numerically simulate multiphysical polycrystalline material behavior, the so-called condensed method is taken as a basis for the investigation and finally optimization of controllable parameters of ferroelectric energy harvesting cycles. A first idea of a technical implementation taken from literature is considered as cycle of reference, constituting the starting point of the present study, being focused on material aspects rather than on harvesting devices. Different quality assessing parameters are introduced, taking into account general aspects of harvesting efficiency as well as the ratio of irreversible switching-related to reversible piezoelectric contributions. Residual stresses are likewise predicted to give an idea of reliability and the risk of fracture. Two types of cycles and associated optimal process parameters are finally presented.

WITHDRAWN: Performance of electrical energy based unconventional machining processes – Review

• In present paper is discussed about the electrical process parameters. • It is also discussed the Material Removal Rate (MRR), Surface Roughness (SR) and Tool Wear Rate (TWR). • Electrical energy based unconventional machining techniques were discussed. • Taguchi, genetic algorithms and artificial neural network have been used to evaluate the optimal solutions. • The level of machining parameters levels are differs from material to materials. • The level of machining parameters levels are differs from material to materials. • This paper presents a case study of EDM of duplex brass. • The current (10-20A), pulse on time (100–200 µs) and voltage (40–60 V) have been considered for machining of duplex brass. In recent years, the fabrication of components with better quality is a difficult task. The control parameters of the machining processes are maintaining the properties of the finished components. The present paper is discussed about the electrical process parameters such as current, pulse on time, voltage, and their effects on machined surfaces. It is also discussed the Material Removal Rate (MRR), Surface Roughness (SR), and Tool Wear Rate (TWR) with respect to electrical energy based unconventional machining techniques such as Electric Discharge Machining (EDM) and Wire cut EDM for different materials. The optimization methods such as Taguchi, genetic algorithms, and artificial neural networks have been used to evaluate the optimal solutions. The level of machining parameter levels differs from material to materials. A case study of EDM of duplex brass. The current (10-20A), pulse on time (100–200 µs), and voltage (40–60 V) have been considered for machining of duplex brass.

The study of surface roughness and material removal rate using electrical discharge machining on copper-electroplated aluminium under discharge current and pulse-on time variation

This paper presents the effect of conductivity and cutting parameters in electrical discharge machining using material Cu-electroplated Al. Among the machining characteristics determined, the material removal rate (MRR) and surface roughness (SR) have been investigated under the influence of two electrical process parameters; namely discharge current and pulse-on time. The results of the study showed that the higher the value of discharge current and pulse-on time enhance both of the MRR and SR These results were then studied more detail by SEM observation showing the surface morphology of the object after cutting. The MRR results comparison between Cu-electroplated Al and untreated Al specimen proved that the conductivity affects the MRR results, where in general, both of MRR and SR were increased by using Cu-electroplated Al workpiece.

Investigation of powder mixed electrical discharge machining and process parameters optimization using Taguchi based overall evaluation criteria

Electrical Discharge Machining is a type of nontraditional process can be used for machining of hard materials and making of complicated shape.In EDM, the important parameters are tool, workpiece and dielectric liquid. Dielectric liquid is used to enhance ionization during the process. Powder Mixed EDM (PMEDM) is preferred for enhance the process efficiency. In this work, nano alumina (Al2O3) powder is added to the dielectric liquid and the process parameters effects are investigated. Input parameters considered are pulse on time, pulse off time and current. Output parameters considered are rate of material removal, surface quality and wear in electrode. Nano powders are mixed in the ratio of 2% to the EDM oil during the operation with dielectric fluid weight ratio. Process parameters are optimized using Taguchi based Overall Evaluation Criteria (OEC). The result revealed thatPMEDM is enhanced the process efficiency.

Theoretical substantiation of the influence of electric pulse processing on the process of obtaining juice from grapes and fruits

The article presents the theoretical basis of the effect of electrical pulse processing on the process of obtaining juice from grapes and fruits. High-voltage pulsed electrical processing technology for biological products has a higher damaging effect on living cells than other electrical effects, and this can be achieved due to the passage of large discharges of current through tissues and cells in a short period of time. It has been found that high efficiency in killing living cells by secretion can be achieved as a result of a pulsed energy effect. In order to develop energy-efficient electrical technology for extracting juice from fruits and grapes, it has been found that high-voltage electric pulse discharge treatment of grapes and apples before extracting juice has a good effect. Analytical expressions between electrical impulse processing parameters (pulse energy and capacitor capacity) and juice output were determined. The degree of damage to fruit and grape cells depends on the capacitance of the capacitor, the discharge voltage, and the number of pulses.

Analysis of the electrical discharge machining (EDM) performance on Ramor 550 armor steel

Abstract This study investigated the electrical discharge machining (EDM) performance of Ramor 500 Armor steel, a material used in the defense industry for armor production. In addition, the surface quality and amount of material wear of the treated surfaces were determined using different electrical discharge processing parameters for a copper electrode including pulse on-time (99, 150, 225, 300, 351 μs), pulse off-time (10, 15, 23, 30, 35 μs), and discharge current (3, 4, 6, 8, 9 A), at a constant pressure of 1 mm depth of cut. As a result of the experiments, the values related to the material removal rate (MRR) and the surface roughness (Ra) were obtained and the findings analyzed via response surface methodology (RSM). The increase in amperage and pulse on time resulted in an increase in Ra and MRR values. The minimum and maximum Ra and MRR values emerged at currents of 3 and 9 A, respectively. In the experiments performed applying currents of between 3 and 9 A, the white layer widths were measured as 0.0474 mm and 0.0915 mm, respectively. The statistical test results showed that the most effective processing parameters for the MRR were the discharge current amperage (49.01 %) and the pulse off-time (16.51 %), whereas the most effective parameter for the Ra value was the discharge current amperage (79.07 %).

Impact of Electrical Process Parameter in Electrochemical Micromachining of Nimonic 75 Alloy

Electrochemical micromachining is one among the widely known method for machining micro holes in electrically conductive, hard to cut materials. As nimonic 75 alloy can withstand alternate cooling and heating conditions, it finds application in aero combustor liner. In this study, solid tungsten carbide (500µm) was selected as the tool to produce micro holes in the work-piece (nimonic 75 alloy). As pulsed current, results in more confined dissolution, trials were performed by changing electrical process parameter such as duty cycle, pulse on period and pulse off period and their effect on MRR and dimensional deviation were studied. Employing TOPSIS, lower values of duty cycle and pulse on period was desirable for the production of holes with better geometrical features and the similar was found to be in concurrent with SEM images.

Analysis of the electrical discharge machining (EDM) performance on Ramor 550 armor steel

Abstract This study investigated the electrical discharge machining (EDM) performance of Ramor 500 Armor steel, a material used in the defense industry for armor production. In addition, the surface quality and amount of material wear of the treated surfaces were determined using different electrical discharge processing parameters for a copper electrode including pulse on-time (99, 150, 225, 300, 351 μs), pulse off-time (10, 15, 23, 30, 35 μs), and discharge current (3, 4, 6, 8, 9 A), at a constant pressure of 1 mm depth of cut. As a result of the experiments, the values related to the material removal rate (MRR) and the surface roughness (Ra) were obtained and the findings analyzed via response surface methodology (RSM). The increase in amperage and pulse on time resulted in an increase in Ra and MRR values. The minimum and maximum Ra and MRR values emerged at currents of 3 and 9 A, respectively. In the experiments performed applying currents of between 3 and 9 A, the white layer widths were measured as 0.0474 mm and 0.0915 mm, respectively. The statistical test results showed that the most effective processing parameters for the MRR were the discharge current amperage (49.01 %) and the pulse off-time (16.51 %), whereas the most effective parameter for the Ra value was the discharge current amperage (79.07 %).

Carbon Composite Nanofibers Produced By Hybrid-Spinning of Polyacrylonitrile Precursor As Anodes for Lithium Ion Batteries

In this study, polyacrylonitrile (PAN) nanofibers are produced through a novel technique known as Hybrid-Spinning (HS) and used as a precursor for anodes in lithium ion batteries (LIBs). HS is a combination of two fiber-producing technologies: Centrifugal spinning (CS) and Electrospinning (ES). The use of HS for nanofiber production is promising due the limitations of both CS and ES. CS produces a high yield of nanofibers through centrifugal forces but is unable to account for the control of the fiber morphology, which limits the potential of the nanofibers-production through this technology. ES, on the other hand, produces nanofibers through electrical forces, allowing for a high degree of fiber morphology control by alternating the electrical field and process parameters. However, the high cost, safety concerns, and low yield of ES makes it unsuitable for the mass production of nanofibers in industry. Therefore, Hybrid Spinning has a high potential in changing the nanofiber industry by removing the limitations of both ES and FS while also minimizing safety-concerns, cost, and environmental impact. This work documents the morphology and characteristics of PAN nanofibers produced through HS and compares them to nanofibers made through FS and ES. The PAN fibrous mats obtained by HS are then converted into carbon nanofibers by calcination and directly used as free-binder anodes in lithium-ion batteries. The electrochemical performance of the HS carbon-fiber anodes is then compared with that prepared by ES and CS to determine the viability of HS technology with respect to Lithium-ion battery applications.

Effects of High-Voltage Electric Field Process Parameters on the Water-Holding Capacity of Frozen Beef during Thawing Process

In order to investigate the thawing time and water-holding capacity under high-voltage electric field (HVEF), we studied the thawing experiments of frozen beef in a multiple needles-to-plate electrode system. The electric field, thawing characteristics, and quality parameters during the thawing process were measured. The results showed that compared with the control, the thawing time of beef under HVEF was significantly shortened, the thawing rate increased significantly, the drip loss decreased, and the centrifugal loss increased during the thawing process. By the response surface analysis and single-factor analysis of variance, the best thawing conditions for each thawing parameter were determined. It provides a theoretical basis and practical guidance for understanding the characteristic parameters of the high-voltage electric field thawing technology.