EDM Process Research Articles

Evaluation of Prediction Models of the Microwire EDM Process of Inconel 718 Using ANN and RSM Methods

Precise machining of micro parts from difficult-to-cut materials requires using advanced technology such as wire electrical discharge machining (WEDM). In order to enhance the productivity of micro WEDM, the key role is understanding the influence of process parameters on the surface topography and the material's removal rate (MRR). Furthermore, effective models which allow us to predict the influence of the parameters of micro-WEDM on the qualitative effects of the process are required. This paper influences the discharge energy, time interval, and wire speed on the surface topography's properties, namely Sa, Sk, Spk, Svk, and MRR, after micro-WEDM of Inconel 718 were described. Developed RSM and ANN model of the micro-WEDM process, showing that the discharge energy had the main influence (over 70%) on the surface topography's parameters. However, for MRR, the time interval was also significant. Furthermore, a reduction in wire speed can lead to a decrease in the cost process and have a positive influence on the environment and sustainability of the process. Evaluation of developed prediction models of micro-WEDM of Inconel 718 indicates that ANN had a lower value for the relative error compared with the RSM models and did not exceed 4%.

Green manufacturing: a comparative study of renewable dielectrics in the EDM process

Green manufacturing: a comparative study of renewable dielectrics in the EDM process

Experimental investigation on surface morphology and recasting layer of Si3N4-TiN composites machined by die-sinking and rotary EDM

Si3N4-TiN composites have extensive manufacturing applications because of their first-rate mechanical and thermal properties. Conversely, they are very demanding on machines that use conventional practices because of their superior strength and hardness. Electrical discharge machining is a viable substitute for machining of Si3N4-TiN composites through electrical erosion. However, very few studies have been conducted on the machinability and surface characteristics of electrical-discharge-machined composites. This study focuses on the materials processing characteristics of a Si3N4-TiNcomposite using rotary EDM and die-sinking EDM performed with a Cu electrode. In addition, the surface and cross section of the subsurface of the composite were examined, along with energy dispersive X-ray analysis, to identify the elements present on the machined surface. It was found that the high level of hardness and low level of toughness of the Si3N4-TiN composite contributed to the presence of microcracks, globules, pores, recast layers, and craters on the EDMed surface. The recast layer thicknesses of the die-sinking EDM (optimum hole, 106 μm; best hole, 151 μm; worst hole, 166 μm) and rotary EDM (optimum hole, 53 μm; best hole, 55 μm; and worst hole, 58 μm) were examined. In addition, the presence of pores and ablation increased significantly during the rotary EDM process. Rotary EDM parameters capable of producing a minimum white layer thickness were also investigated. Finally, the porosity levels were estimated according to the number of pores using ImageJ software. For the die-sinking EDM, the estimated porosity values for the optimum, best, and worst holes were 14.989%, 19.525%, and 21.706% respectively and for the rotary EDM, these values were 24.873%, 33.04%, and 37.99% respectively.

Effect of Pulse Current and Electrode Material in Producing of Microplate Implant by EDM Die-Sinking

The main problem in microplate implant production is the high cost of production. It is because the production process uses two machining processes. Microplate production currently uses wire-EDM and micro-milling. Therefore, microplate production with die-sinking EDM has been developed to reduce production costs. This paper proves that microplate implant can be produced by die-sinking EDM. This research also examines the response of pulse currents and electrode materials on the Material Removal Rate (MRR), the surface roughness (Ra) and the White Layer (WL) in the microplate. EDM process uses pulse currents of 6, 9, and 13 A with copper and graphite electrodes. The results show that the microplate has been successfully produced by using die-sinking EDM in a pure titanium sheet with a thickness of 0.4 mm. MRR, Ra and WL are directly proportional to pulse current. The results are greater when using the graphite compared to the copper electrode. MRR, Ra, and WL are in the range of 0.22-0.99 mm3/minute, 5.28-11.13 μm, and 21.66-33.66 μm, respectively. The pulse current of 6A with the copper electrodes produces the microplate of the best quality.

Fabrication of micro-textured surfaces using Gravity-assisted EDM process with foil electrode to induce hydrophobicity on Cu surface

The fabrication of texture on metallic surfaces to achieve hydrophobicity has piqued the interest of many researchers. The Laser machining process is widely used for this purpose and is also appreciated for nonmetals. However, due to the metal’s high conductivity, the Laser machining process has been limited to some extent. Texturing a metallic surface with Electro-discharge machininghas received little attention. In this work, the texture on the surface of Cu material is fabricatedusing a gravity-assisted EDM process with a foil tool. The fabrication of microchannels in two mutually perpendicular directions resulted in textured surfaces. The width of the microchannels iskept constant, while the spacing between them was varied, resulting in two-dimensional arrays ofsquare-shaped micro-pillars of varying sizes. Three distinct textured surfaces are created, with channel widths of 59.67 μm in all cases but micro-pillar widths of 80.29 μm, 60.72 μm, and 40.57 μm, respectively. The hydrophobic nature of the textured surfaces is also investigated and compared to that of the untextured surface. It has been revealed that texturing the Cu surface improves its hydrophobicity. Hydrophobicity increased with decreasing micro-pillar width for a constant channel width.

Present and future prospective of shape memory alloys during machining by EDM/wire EDM process: a review

Present and future prospective of shape memory alloys during machining by EDM/wire EDM process: a review

Review on Recent Development in the Wire EDM Process

Review on Recent Development in the Wire EDM Process

Experimental Studies on TIG Welding of Advanced Material under various parameters

The material stainless steel (AISI 309) is extensively used in almost all types of thermal power plant, petroleum industries, waste treatment industries etc. The material AISI 309 stainless steel is used as sample which is prepared by wire cut EDM process. The sample dimension is tested according to the ASTM standard. Tungsten inert gas (TIG) welding is used to improve mechanical properties and to reduce the manufacturing costs, by the taguchi`s experimental design method which is used for optimization. The three different welding process parameters such as GFR, WS and WC have opted to perform the tests using L9 orthogonal array. The tensile strength and bending strength test are conducted to check the final weld quality. The maximization of ultimate tensile strength, impact strength and bending strength of weld joints results has obtained by input parameters such as welding current 170amp, welding speed 2 mm/sec and gas flow rate 15 lit/min. It is observed that current and welding speed influence to maximize mechanical properties of weld joints.

A novel approach for modeling MRR in EDM process using utilized discharge energy

The discharge energy generated during the EDM operation characterizes the productivity of the process. The present research attempts to model the material removal process of EDM by obtaining the actual discharge energy during the spark occurrence. The model incorporates the actual discharge conditions by analyzing the real-time V–I waveforms acquired during the EDM operation to determine the discharge power. The model also establishes that discharge power density is a function of applied heat flux and discharge gap. The model verification is conducted by performing a series of experiments on Titanium grade-5 alloy using a full factorial L18 design. The current study implements tool lift time compensation to achieve accurate MRR from the experimental outcomes. The specific energy obtained using the current approach shows better stability compared to previous literature. The parametric studies show gap voltage to be the most significant parameter in influencing the MRR. The main effects plot show the influence of different process parameters on MRR. Additionally, the surface morphology of workpiece and tool surface through SEM and EDS analysis shows the presence of different anomalies and confirms surface alloying. The predicted outcomes of the model show a maximum deviation of 13.05% from the practical evidence.

Multi-Objective Optimization of the Process Parameters in Electric Discharge Machining of 316L Porous Stainless Steel Using Metaheuristic Techniques.

Electric discharge machining is an essential modern manufacturing process employed to machine porous sintered metals. The sintered 316L porous stainless steel (PSS) components are widely used in diverse engineering domains, as interconnected pores are present. The PSS material has excellent lightweight and damping properties and superior mechanical and metallurgical properties. However, conventional machining techniques are not suitable for porous metals machining. Such techniques tend to block the micro-pores, resulting in a decrease in porous materials’ breathability. Thus, the EDM process is an effective technique for porous metal machining. The input process parameters selected in this study are peak current , pulse on time , voltage , flushing pressure , and porosity. The response parameters selected are material removal rate (MRR) and tool wear rate (TWR). The present work aims to obtain optimum machining process parameters in the EDM of porous sintered SS316L using two meta-heuristic optimization techniques, i.e., Teaching Learning-Based Optimization (TLBO) and Particle Swarm Optimization (PSO) algorithms, to maximize the MRR and minimize the TWR values. In the case of PSS having a 12.60% porosity value, PSO and TLBO algorithms give same optimum machining parameters. However, for PSS having an 18.85% porosity value, the PSO algorithm improves by about 5.25% in MRR and by 5.63% in TWR over the TLBO. In the case of PSS having a 31.11% porosity value, the PSO algorithm improves about 3.73% in MRR and 6.46% in TWR over the TLBO. The PSO algorithm is found to be consistent and to converge more quickly, taking minimal computational time and effort compared to the TLBO algorithm. The present study’s findings contribute valuable information in regulating the EDM performance in machining porous SS316L.

Influence of ZnO nanoparticle addition and spark peak current on EDM process of AISI 1045, AISI 4140, and AISI D3: MRR, surface roughness, and surface topography

Influence of ZnO nanoparticle addition and spark peak current on EDM process of AISI 1045, AISI 4140, and AISI D3: MRR, surface roughness, and surface topography

Investigation of Mechanical and Tribological Characteristics of Medical Grade Ti6al4v Titanium Alloy in Addition with Corrosion Study for Wire EDM Process

Metals used in biomedical applications are frequently coated to prevent oxidation and metallic ion release, both of which can be harmful due to toxic effects. To prevent these adverse effects of metals, researchers have focused their efforts on developing various coating techniques, facilitating surface coating, or obtaining functional surfaces. (WEDM) is now considered a difficult method of obtaining functional surfaces for medical applications. The properties of the surface and subsurface layers obtained by the WEDM method are particularly interesting in this regard. The analysis utilised RSM-based computational technique to evaluate the WEDM characteristics (MRR SR) of Ti6Al4V Titanium Alloy in biomedical applications. The biggest drawback of the material in the biomedical industry, which includes orthopedic applications and dental implants, would be that it releases harmful atoms such as iron, chromium, and nickel into the bodily fluid environment. To combat the problems, a hydroxyapatite layer applied to the metal implant improves biocompatibility, osteocompatibility, and antimicrobial properties. By comparing the Modified Differential Evolution (MDE) approach to the basic differential evolution (DE) optimization strategy, the effectiveness of the MDE approach has been established. According to the cyclic polarized test, the Hap coated Titanium material had better corrosion resistance than the pure sample. The Hap coated titanium material has a higher zone of inhibition than the pure sample. The next step is to synthesis hydroxyapatite from cuttlebone, which is then electrodeposited onto titanium. FTIR, electrochemical tests, FESEM, and SEM were used to describe the coated sample, as well as an antibacterial test using E. Coli and B. Cereus bacteria. Because it is porous, the Hap coating helps bone tissue growth by preventing detrimental metal ions from escaping into the biological medium. The corrosion inhibition efficiency of the coated sample was performed in SBF (NaHCO3—0.35 g/L, MgCl2.6H2O—0.30 g/L, CaCl2·2H2O—0.37 g/L, K2HPO4. 3H2O—0.23 g/L, Na2SO4—0.071 g/L, NaCl—7.99 g/L, KCl—0.22 g/L, Tris’s buffer—6.063 g/L) solution using the potentiodynamic polarisation method and the solution pH was maintained.

Performance Prediction in EDM Process for Al 6061 Alloy Using Response Surface Methodology and Genetic Algorithm

The Electric Discharge (EDM) method is a novel thermoelectric manufacturing technique in which materials are removed by a controlled spark erosion process between two electrodes immersed in a dielectric medium. Because of the difficulties of EDM, determining the optimum cutting parameters to improve cutting performance is extremely tough. As a result, optimizing operating parameters is a critical processing step, particularly for non-traditional machining process like EDM. Adequate selection of processing parameters for the EDM process does not provide ideal conditions, due to the unpredictable processing time required for a given function. Models of Multiple Regression and Genetic Algorithm are considered as effective methods for determining the optimal processing variables of Electrical Discharge Machining. The material removal rate (MRR) and tool wear (Tw) were investigated using the process variables of pulse on time (Ton), pulse off time (Toff), and current intensity (Ip). The established empirical models were used to perform Genetic Algorithm (GA) to maximize (MRR) and minimize (Tw). The optimization results were utilized to establish machining conditions, validate empirical models, and obtain optimization outcomes. The optimal result that appears in this work was the pulse on (176.261 μs), pulse off (39.42 μs), and current intensity (23.62 Amp.) to maximize the MRR to (0.78391 g/min) and reduce tool wear to (0.0451 g/min).

Experimental Investigation of Powder-mixed Dielectrics for Electrical Discharge Machining

The addition of various micro/nanopowders in the EDM dielectric results in superior machining performance over the conventional pure liquid dielectrics. While most of the experimental studies on powder-mixed dielectrics in EDM have used conductive or semi-conductive powders, a few have shown merit in using non-conductive powders as well. However, unlike conductive powders, the specific mechanisms through which the non-conductive powders and their concentration affect the EDM process is poorly understood. The research presented in this paper investigates the effect of non-conductive powders and their concentration on the machining performance of powder-mixed dielectric-based EDM (PMEDM) in terms of material removal rate, tool wear, and surface roughness. Experiments are conducted with Alumina and SiC powder added to DI water at three different concentrations. It is observed that the material removal rate (MRR) and tool wear rate (TWR) of PMEDM is higher than conventional EDM with pure dielectric, while the electrode wear ratio is lower. The machined surface finish is smoother in PMEDM than conventional EDM. In Alumina-based PMEDM, an increase in the powder concentration leads to inter-electrode gap enlargement due to increased electrical conductivity, and leads to higher pulse frequency, stable machining conditions and improved MRR. In addition, dispersion of discharge energy due to the powder results in a better surface finish. The conductivity of SiC-mixed dielectric remains unaffected with changes in powder concentration, leading to no significant improvements in MRR. However, the energy dispersion mechanism leads to a smoother surface as the powder concentration increases.

Optimization of EDM process parameters based on variable-fidelity surrogate model

Optimization of EDM process parameters based on variable-fidelity surrogate model

Performance and increased fatigue life for a Ti workpiece produced by the EDM process

Performance and increased fatigue life for a Ti workpiece produced by the EDM process

Formation of Oxide Layer and Wettability on the Surface of Electrical Discharge Machining-Based Implant Engineered by Micro-Finishing

The ability to promote rapid osseointegration is an important criterion on the titanium implant surface. This performance is greatly determined by the roughness, wettability, and composition of the implant surface. This study aims to investigate the oxide layer formation and wettability on the EDM-titanium implant surface engineered by different micro-finishing methods (i.e. mechanical, physical, and chemical processes). The oxide layer formation was investigated by observing the wt% of oxygen formed while the wettability criterion was studied by determining the contact angle between the liquid and solid surface. The result reveals that the oxide layers formed on the sample surface, excepting Sulfuric acid (H2SO4) 95%-etched, show an interaction with the surface roughness and its wettability. The smoother the surface roughness of the sample, the lower the percentage of the oxide layer and the contact angle formed on the sample surface. In this aspect, the ultrasonic cleaning benchmark has the highest percentage by altering 18.84% of the oxide layer formed by the EDM process while the decrease of 75.89% generated by the H2SO4-etching is the lowest one. On the other hand, the higher the percentage of the oxide layer formation, the lower the wettability of the sample surface. In this aspect, the ultrasonic cleaning benchmark has the lowest wettability with a contact angle of 124º (hydrophilic) while HCl-etching is the lowest with 45º (hydrophobic). The results are notable that the ultrasonic cleaning method is able to alter wt% of the oxygen on the EDM-titanium implant surface, whereas the acid etching method can be recommended as a worthy method of the surface finishing for the semi-permanent type of implant.

Influences of tool electrodes on machinability of titanium α- β alloy with ISO energy pulse generator in EDM process

It is tedious to machine high strength materials such as titanium alloy for making engineering products related to aerospace and medical applications due to its high corrosion resistance and low density. In this study, an endeavor was made to analyze the influence of tool electrodes in electrical discharge machining process for enhancing the machinability of Titanium α- β alloy. Copper, brass and tungsten carbide electrodes were utilized with iso energy pulse generator. It was observed that the use of copper electrode could enhance material removal mechanism due to its higher electrical conductivity. The better surface topography with tiny craters could be observed on machined specimen with tungsten carbide electrode owing to its high melting point. The IEPG generator can produce tiny craters with lower pulse energy and uniform energy distribution. Since it produces tiny crater and has higher melting point, the tungsten carbide tool electrode can create lower surface roughness than other electrodes. Brass electrode can create larger craters on the machined surface of titanium alloy specimens due to its low melting point. Hence it could create higher surface roughness and electrode wear.

Comparison between Bang-Bang, PID and LQR Controller for Electrical Discharge Machining Process

Abstract: During the Electric Discharge Machining process, ensuring that there is the appropriate amount of spark gap between the tool and the workpiece is one of the most important factors in determining how well the machine will perform. With the assistance of Simulink models, this work will compare the effects of a Bang-Bang Controller, a Proportional-Integral-Derivative (PID) Controller, and a Linear Quadratic Regulator (LQR) Controller on a dynamic EDM process. Through the use of simulation, it was possible to observe the effectiveness of each controller in correctly maintaining the spark gap distance. This effectiveness was then used to determine the approximate values by which the controller could be implemented on the physical EDM setup. In light of the fact that the EDM is a model of a non-linear process, it has been established beyond a reasonable doubt that LQR is the controller of choice for this process. The various controllers for the EDM Process Model were compared, and supporting graphs are provided to strengthen the claims made in the article.

Estimation of MRR and thermal stresses in EDM process: a comparative numerical study

Estimation of MRR and thermal stresses in EDM process: a comparative numerical study