Die Sinking Research Articles

Analysing Energy Consumption and Productivity in Die Sinking Electrical Discharge Machining of PCD materials

Analysing Energy Consumption and Productivity in Die Sinking Electrical Discharge Machining of PCD materials

Fabrication of Die Sink Electrochemical Machining Tools Using Low Melting Fusible Alloy and Polymer Based Additive Manufacturing

The present work introduces a novel approach to fabricating die-sink tools for electrochemical machining (ECM) using low-melting fusible alloy and additive manufacturing. Three methods are proposed, each bettering the previous in manufacturing sustainability. The versatility of the process enables the fabrication of die-sink ECM tools that are hitherto considered challenging to fabricate. Finite element analysis was used to simulate the temperature rise of the low-melting (50 °C) tool due to Joule heating, accounting for electrolyte flow under various process parameters. A novel validation method employed a thermostat temperature probe as a cathode. Experiments based on the simulation data revealed that for a 4 mm tool diameter, the tool is unlikely to melt at 3 A current, 200 μm inter-electrode gap, 11.97 S m−1 electrolyte conductivity, and 1.7 m s−1 electrolyte velocity. A pulsed power supply was subsequently used to improve heat dissipation, and ECM was successfully carried out using tools of various shapes, demonstrating the effectiveness of the developed fabrication methods.

Parametric analysis of electrical discharge machining on AA6061 with a WC–Cu composite electrode

The AA6061 aluminium alloy surface characteristics presented in this study were obtained after it was machined using die sinking electro discharge machining (EDM) with a composite electrode developed through powder metallurgy. Machining was performed using negative polarity. In order to obtain optimum material removal rate (MRR) and surface roughness (SR), the research has been carried out, and EDM parameters like voltage, current and pulse on time were optimized using the response surface methodology that integrates the central composite design. The parameter interaction effects on EDM machined surface characteristics were studied with the aid of ANOVA. It was determined from model that the regression for MRR and SR were 98.6% and 98.3% respectively, means empirical model is considered sufficient. It was observed that increased MRR and SR were observed in the condition of increased current, but MRR and SR decreased at increased voltage and pulse on time. This could be due to strengthened ionization temperature that increased MRR with acceptable SR. The microstructure of the machine was assessed using microscopic evaluation. The increased current contributed to the formation of a recast layer and debris which hinders the machining process and reduces MRR. The experimental results show that the maximum MRR of 0.087 mg/min and minimum SR of 1.893 µm were achieved. Additionally, the use of WC–Cu composite electrodes led to an increase in hardness from 65 HV to 78 HV in the machined region. It is concluded that WC–Cu composite electrodes typically result in higher hardness, improved MRR and better SR for the AA6061 alloy compared to conventional Cu electrodes.

The Enhancement of Die Sink EDM Machining Efficiency Incorporating Micro-Flakes of Graphite Powder

The Enhancement of Die Sink EDM Machining Efficiency Incorporating Micro-Flakes of Graphite Powder

Design of experiments integrated with neural networks for optimization and predictive modelling of electrode wear of novel Ti-6Al-4V-SiCp composites during die sinking electric discharge machining

Die Sink Electric Discharge Machining is a widely used manufacturing process for shaping hard and electrically conductive materials. This study investigates the effects of various electrode materials such as, Ti-6Al-4V-SiCp, Brass and Copper on the machining performance of AISI 316 l Stainless Steel workpieces using EDM. The methodology involved optimizing parameters such as Electrode Material, Discharge Current, Gap Voltage, Spark Gap, Pulse-on Time, and Pulse-off Time. From the extensive experimantation it was observed that the combination of Ti-6Al-4V-SiCp electrode material, 8Amp Discharge Current, 90 V Gap Voltage, 75 μm Spark Gap, 100 μs Pulse-on Time and 15 μs Pulse-off Time has resulted in lowest electrode eear rate, higher machining time, and low electrode surface roughness ratio. Ti-6Al-4V-SiCp electrodes possess higher hardness and electrical conductivity compared to Brass and Copper Electrodes leading to higher wear resistance against repeated thermal shocks during electric discharge machining operation. Feed Forward Artificial Neural Network is successfully applied to predict the output characteristics of the experimentation with high accuracy of 98.3% (Electrode Wear Rate), 94.6% (Machining Time) and 93.8% (Electrode Surface Roughness Ratio). Further, microstructure analysis concludes that lowest wear is observed in Ti-6Al-4V-SiCp electrodes compared to Brass and Copper electrodes.

Investigations of process parameters on surface finish of aluminium component produced by die sink electric discharge machining process

Investigations of process parameters on surface finish of aluminium component produced by die sink electric discharge machining process

Recent Advances in Machining of Composite Materials by Electrical Discharge Machine

Composites are being used since decades and imparting excellent properties comparatively. It may be used in numerous industries because of its light weight and specific strength. Machinability of these materials is a concerned aspect. Conventional and The composites have been machined using unconventional machining techniques. Conventional methods are less suitable than non-conventional quoting the best surface finish and ability to machine complex parts. This article investigates the suitability of thermo-electric process for the machining of composites for higher surface quality and material removal. It includes the study of machining by die sinking, wire cut, powder mixed electric discharge machine in different matrix based composites along with the variation of reinforcement. Electric Discharge Machining (EDM) finds its suitability in machining of different metal matrix composites (MMC) more than the Polymer Matrix Composite (PMC) and Ceramic Matrix Composites (CMC). Variation in input parameters listed as Pulse duration, Voltage, Peak Current and Polarity is studied to obtain the optimum resulting parameters as Material Removal Rate (MRR), Surface Roughness (SR), Electrode Wear Rate (EWR) and Kerf Width. Material removal in PMC is 16% more in parallel fibre direction than with perpendicular. Low electrical conductance and high hardness of CMCs limits the use of EDM while natural ceramics are found more suitable for machining. Gap voltage, pulse on time and current are found most crucial in machining MMCs while quantifying material removal and surface roughness.

Die-sinking and rotary EDM surface and subsurface analysis of MoSi2-SiC ceramic composites

Rotating EDM and die sinking EDM were used to compare the machinability of MoSi2-SiC composites. Surface flaws such as micro cracks, un melted spherical particles, pores, a recast layer and craters following EDM can be attributed to the high hardness and poor toughness of the MoSi2-SiC. Die sinking EDM and rotary EDM, as shown by a comparison of recast layer thicknesses, produce the most uniformly thin white layers, at 92 and 30 µm respectively. The study found that the area fraction yield for porosity ranged from 8.18% to 12.922% when using rotary EDM, but only from 2.33% to 8.10% when using die-sinking EDM. According to the EDAX, the spongy exterior of a composite is the result of a lot of gas being produced. Although the rotational movement of the tool sweeps the resolidified particles away, Rotary EDM resulted in a thinner and less uniform recast layer while still producing good surfaces.

SURFACE IMPROVEMENT OF AISI D3 STEEL EMPLOYING SiC BLENDED DIELECTRIC IN ELECTRIC DIE SINKING PROCESS

AISI D3 die steel is extensively used in long-run dies for blanking, forming, deep drawing, and thread rolling. Among all the non-traditional machining processes, the Electric Die Sinking Process (EDSP) is mostly employed to manufacture these long-run dies. The EDSP method produces a surface of high quality, which impacts product performance significantly. The surface roughness of AISI D3 die steel is examined in relation to a number of parameters, including peak current, pulse-on duration, gap voltage, and powder concentration. Copper is selected as the tool. Orthogonal array concept coined by Taguchi has been deployed to execute the experiments. It is clearly understood from the results that powder concentration has a key impact on machined surface quality by lessening the generated cracks and enhancing the surface finish by 20%. Further, peak current has more impact on the performance characteristics than pulse-on time and the gap voltage.

Experimental investigations and multi criteria optimization during machining of A356/WC MMCs using EDM

In the current paper, the authors are intended to manufacture the aluminum based metal matrix composite (MMC) employing the stir casting process. Further, the fabricated composite sample is investigated for machining characteristics during the die sink electrical discharge machining process (EDM). EDM is most commonly employed to satisfy the special needs of industry such as developing deep holes and complex contours from high strength materials such as composites, alloys, smart materials, and functionally graded materials. In the current study A356 and 4%, tungsten carbide (WC) powder are considered as matrix and strengthening materials respectively to fabricate the MMCs. During the machining activity, the input factors like discharge current (Ip), Voltage (Vg), Pulse On-Time (Ton), and flushing pressure (P) are optimized for achieving optimum surface roughness (SR), Tool Wear Rate (TWR) and Material Removal Rate (MRR). To estimate the ideal set of process factors grey regression analysis (GRA) is used. From the results, it was observed that the GRA is found to perform better than the RSM.

Influence of surface roughness of die sinking EDM on mold releasability in compression molding of thermosetting phenol resin

Improvement in metal mold characteristics such as wear resistance, corrosion resistance and mold releasability is essential for plastic molding. In this study, factors of the mold releasability were investigated by quantitative evaluations of adhesion forces between the processed metal mold surfaces and the molded resins in compression molding of thermosetting phenol resin. Die sinking EDM was employed as the processed surfaces of the metal molds. As the mold releasability tests, the molded thermosetting phenol resin onto the EDMed surface was pulled up in the perpendicular direction from the surface. Consequently, the mold releasability could be quantitatively evaluated by measuring a maximum tensile load which means a mold release force when the molded resin is separated from the EDMed surface.Several workpieces with different surface roughness as the EDMed surfaces were prepared by varying discharge currents and pulse durations. As a result of investigations on relationships between surface roughness parameters and measured mold release forces, the mold release forces tended to increase as maximum height roughness RZ and average length RSm of the surface roughness parameters increase. On the other hand, the mold release forces tended to decrease as peak count RPc increases. Accordingly, it is considered that anchor effects become higher with increase of undulation on the EDMed surfaces. Therefore, the undulation is one of the factors affecting the mold releasability, and it would be possible to improve the mold releasability by reducing the undulations on the EDMed surfaces with EDM conditions.

The outcome of dielectric fluids in electrical discharge machining performance: A review

Electrical discharge Machining is a non-traditional machining process in which the material is removed by electrical discharge at short intervals in presence of a dielectric medium. The electrode is moved towards the gap until it becomes so small that the dielectric is ionized due to the immersion of voltage. EDM is mostly used in the die sinking industry to machine hard materials, however, it has lately been utilised to machine light materials like Ti alloy. Dielectric fluid plays an important role in the rate of material removal and the qualities of the machined surface in EDM. This study includes a review of the literature on the usage of dielectric fluid and its influence on the features of electrical discharge machining. Dielectric fluids have properties such as viscosity, good wetting capacity. examples of gaseous dielectric are oxygen, helium, argon. As dielectric fluid performs a very great function in any electrical discharge machining operation, the choice of dielectric medium is an essential consideration for EDM performance. Material removal rate and surface finish is essential response in EDM process and dielectric fluids has effective role of them. That is why dielectric is very important in the EDM process.

Influence of different tool electrodes on machining of oil hardened non shrinking steel using die sink electric discharge machine

Tool steel has been a crucial material for many industrial applications and manufacturing of machining tools and milling cutters although very few machining techniques are available for machining of these materials. In this study, the performance of copper and brass tool electrodes on the die sink electric discharge machining of oil-hardened non shrinking steel (OHNS) has been evaluated. Current, pulse on time, and pulse off time were considered as the factors and the responses as material removal rate (MRR) and tool wear rate (TWR). The design of experiments technique namely the Box-Behnken design (BBD) under response surface methodology (RSM) was utilized. The response models were developed for MRR and TWR for brass and copper tool electrodes. The MRR and TWR for brass and copper tool electrodes were compared and represented graphically. The results show that current is the significant factor affecting both MRR and TWR and compared to brass, copper is a suitable electrode for die sink electric discharge machining of OHNS. The confirmative tests validate the developed response models of MRR and TWR.

Study the effects of Process Parameters on Overcut of Al6061 Alloy by (Fe2O3) Nano- Powder-Mixed Micro-EDM

The effect of process parameters on micro-EDM namely current (I), voltage (V) and pulse on time (TON) were studied based on Tool Overcut (OC). The effect of Fe2O3 nano-powder mixed dielectric on the overcut for AL6061 alloy was studied using a Die Sinking (EDM) Machine. Effect of the process parameters was examined by 2-Level Factorial Design using Design of Experiment (DOE) software, whereas the level of importance was statistically evaluated using ANOVA. The results indicate discharge current and pulse on time significantly influenced the EDM process compared to voltage. It was also concluded that the use of Fe2O3 nano-powder mixed micro-EDM decreased the overcut values.

Experimental Study During Electrical Discharge Machining of Reinforced Carbon Fiber Plastic Material

Abstract: The proper selection of machining conditions and machining parameter is an important aspect, before going to machine a carbon-fiber composite material by Die sinking electrical discharge machining (EDM). Because these conditions will determine such important characteristics as; Material removal rate (MRR), Electrode wears rate (EWR), and Surface roughness (R). The purpose of this work is to determine the optimal values of machining parameters of electrical discharge machine, while machining carbon-fiber-composite with copper electrode. The work has been based on the affect of four design factors: pulse current(Ip) supplied by power supply system of electrical discharge machine (EDM), pulse-on-time(TON), gap voltage(Vg) and duty cycle () on such characteristic like material removal rate (MRR), electrode wear rate(EWR), and surface roughness(Ra) on work-piece surface. This work has been done by means of the technique of design of experiment (DOE), which provides us to perform the above-mentioned analysis with small number of experiments. In this work, a L9 orthogonal array is used to design the experiment. The adequate selection of machining parameters is very important in manufacturing system, because these parameters determine the surface quality and dimensional accuracy of the manufactured part. The optimal setting of the parameters are determined through experiments planned, conducted and analyzed using the Taguchi method. It is found that material removal rate (MRR) reduces substantially, within the region of experimentation, if the parameters are set at their lowest values, while the parameters set at their highest values increases electrode wear rate (EWR). Keywords: EDM, Material removal rate, Surface roughness, Tool wear rate,

Electrical Discharge Machinable Ytterbia Samaria Co-Stabilized Zirconia Tungsten Carbide Composites

Composite ceramics of stabilizer oxide coated ytterbia-samaria costabilized zirconia (1.5Yb1.5Sm-TZP) and 24–32 vol% of tungsten carbide as an electrically conductive dispersion were manufactured by hot pressing at 1300–1400 °C for 2 h at 60 MPa pressure. The materials were characterized with respect to microstructure, phase composition, mechanical properties and electrical discharge machinability by die sinking. Materials with a nanocomposite microstructure and a strength of up to 1700 MPa were obtained. An attractive toughness of 6–6.5 MPa√m is achieved as 40–50% of the zirconia transformed upon fracture. The materials show fair material removal rates of 1 mm³/min in die sinking. Smooth surfaces indicate a material removal mechanism dominated by melting.

Thermal Modelling and Multi Decision Making Optimization of EDM of Non Conductive SiC-CNT Ceramic Composite Used for Li-ion Battery and Sensor

In this research work the thermal modeling of a nonconductive Silicon carbide Ceramic matrix composite (CMC) machined by Die Sinking Electric Discharge Machining (EDM) has been done. Though SiC is a non-conductive material but the presence of CNT makes it a conductive material which can be machined with EDM. The modeling procedure carried out by considering some realistic approach like Gaussian heat Flux, Specific Discharge Energy, Variable Latent heat etc. For this analysis a 2D continuum has been designed as work domain. By simulating the work domain model by a Finite Element Analysis (FEA) Software (COMSOL), material removal rate (MRR) has been estimated with variable thermal properties. Parametric analysis of effect of Variable Specific heat on MRR by considering different current, Voltage and Pulse-On time has been performed. The effect of different input parameters (peak current and Pulse-on time) on Crater geometry has been done. A new concept of Specific discharge energy has been introduced during modelling to make it a more realistic model which can also be used as electrode support for electrochemical energy devices as Polymer Electrolyte Membrane Fuel Cells on Li-ion battery. Desirability analysis has been done to get an optimize set of input parameters for I= 3A, V=30V, Ton= 75 µs for machining ceramic matrix composite by EDM. The optimized MRR at this setting is 7.25 mm3/min whereas PFE is 87%. The experimental analysis has been also performed to strengthen the thermal and mathematical modelling.

Mechanical properties and electrical discharge machinability of SPS sintered Y-TZP- and YGd-TZP-titanium nitride composites

Electrical discharge machining (EDM) of ceramics provides an opportunity to manufacture complex shape components from sintered blanks provided the material has a sufficiently high electrical conductivity. In this study yttria and yttria-gadolinia co-stabilized zirconia powders (Y-TZP, YGd-TZP) were produced by intensive co-milling. Fully dense composite ceramics with TZP matrix and 28–32 ​vol% titanium nitride dispersion were manufactured by spark plasma sintering and subsequently ED-machined by die sinking in oil based dielectric.The materials offer high strength of 1200–1450 ​MPa coupled with an attractive fracture resistance of 7–7.8 ​MPa√m. The ceramics exhibit a high electric conductivity of 21–74 ​kS/m with the highest values observed for the co-stabilized matrix and the higher TiN content. ED machining can be carried out at high machining rates of >1 ​mm³/min. The dominant material removal mechanism is melting. ED-machining leaves only a very thin glass-like process zone at the surface, the bulk material stays widely unaffected.

Influence of low-frequency vibration in Die Sinking EDM: a review

Electric discharge machining (EDM) is a thermal-based machining process where material removal in the form of melting and vaporization occurs due to repeated electrical sparks between electrode and workpiece. EDM process finds wide applications in the manufacturing, automobile, aerospace, and biomedical industries due to its remarkable feature of producing complex geometrical shapes like molds, tools, and dies. Irrespective of materials hardness. In this review, the paper author has given details about a new advancement made in the EDM process, which is low-frequency vibration-assisted Die Sinking EDM. There is also a brief introduction of vibration setups that can be used to generate low-frequency vibration. There is also some discussion about various optimization techniques (e.g., TOPSIS, MOORA, GRA) used to optimize the process parameters that are current, frequency, pulse on time, and pulse off time to get better response parameters ( MRR, TWR, and SR). Besides, there is extensive discussion about the effect of current, pulse on time, pulse off time and frequency on MRR, SR, and TWR. In the end, some discussion on the effect of low-frequency vibration on surface topography is also discussed.

Parametric Optimization of Die Sinking EDM in AISI D2 Steel considering Canola oil as Dielectric using TOPSIS and GRA

A colossal research work is being consummated to propose the optimal machining parameters while necessitating current machining techniques to attain elegant products. This research work foregrounded the optimum process parameters of die sinking EDM with 8mm diameter copper electrode during machining AISI D2 steel. Taguchi’s L9 OA method was adopted to design 9 experiments in total and Pulse on time (Ton), Servo voltage (SV) and Peak current (IP) are chosen as input parameters. Three levels of each parameter were selected for designing the experimentation. A natural vegetable oil named Canola oil which is an extract from Canola seeds is taken as dielectric and all the values of Material Removal Rate (MRR), Tool Wear Rate (TWR) and Surface Roughness (SR) for each experiment were noted as the output responses. Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) and Grey Relational Analysis (GRA) which are two Multi-Criteria Decision Making (MCDM) methods were accompanied for determination of ideal parameters for machining AISI D2 steel. Ultimately it is espied that the coalescence of level 3 of pulse on time, level 2 of Peak Current and level 2 of servo voltage propounds the optimum result by performing TOPSIS and GRA.