Pmedm Research Papers - Academia.edu (original) (raw)

Material with unique metallurgical properties such as Titanium, Haynes-25, Molybdenum, Columbium C-103, hardened steels, and other superalloys was developed to meet the demands of extreme applications in aerospace, automobile, and nuclear reactor industries. Machining these materials using a conventional machining process is a challenging task. Electrical discharge machining (EDM) is one of the most suitable non-conventional processes to achieve precise quality components with optimum tooling cost. EDM process becomes a natural choice for machining of superalloys; its low machining removal rate and poor surface quality have been the key problems restricting its development. To overcome these drawbacks, the nanopowder suspended dielectric oil is used, which increases its conductive strength and increases the discharge gap between the tool and workpiece. This newly developed material removal process is called Powder Mixed Electrical Discharge Machining (PMEDM). This paper presents the review work done to improve the performance characteristics of machining like MRR, TWR, EWR, SR, Microhardness, and SCD for different Machining parameters. This paper also reviewed the industrial and academic work performed by various researchers from the origin to the development of PMEDM over the past decades. The research findings with major challenges along with the future scope have also been paved out.

- by
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- Microhardness, Pmedm, Material Removal Rate, Surface Water Quality

Powder mixed electric discharge machining (PMEDM) is one of the new innovations for the enhancement of capabilities of electric discharge machining process. This paper is an attempt to study the effect of SiC powder mixed in the kerosene dielectric fluid. The type of electrodes, the peak current and the pulse-on time are the main selected EDM input parameters. The workpiece and the electrodes materials are the AISI D2 die steel and copper and graphite materials, respectively. The output responses considered are the workpiece surface roughness (SR), the material removal rate (MMR) and the tool wear ratio (TWR). The experiments are planned using response surface methodology (RSM) design procedure. Empirical models are developed for SR, MRR and TWR using the analysis of variance (ANOVA) and regression models to study the effect of process parameters. The best results for the productivity of the process (MRR) obtained when using graphite electrodes at pulse current (22 A), pulse on duration (120 µs) and with silicon carbide (SiC) powder mixing in kerosene dielectrict at reaches (76.76 mm³/min). These results improved the material removal rate by (264%) with respect to the corresponding value obtained when using copper electrodes with kerosene dielectric alone. The best (TWR) results of the process obtained when using graphite electrodes at pulse current (8 A), pulse on duration (40 µs) and using the kerosene dielectric alone reduced to the level (0.1023 %). The use of graphite electrodes, the kerosene dielectric alone, the pulse current (8 A), and the pulse on duration (40 µs) yield the best (SR) with a value (2.87 µm) and improvement by (27%) with respect to the corresponding value obtained when using copper electrodes and the same parameters and machining conditions.

Electrical Discharge Machining (EDM) is a non-conventional manufacturing process based on removing material from a part by electrical discharges between the tool called tool electrode and the part being machined in the dielectric fluid... more

Electric discharge machine (EDM) is a modern machining process with various advantages, as a result of which, its use is becoming more and more wide spread. This paper concerns with the influence of EDM input parameters (type of electrodes, peak current, pulse-on time and powder mixing concentration) on the induced surface residual stresses. The silicon carbide powder is mixed with the kerosene dielectric in powder mixing EDM (PMEDM) process. The experimental work was designed by using the response surface methodology (RSM). The analysis of variance (ANOVA) was used and regression models were built to
predict the surface residual stresses as a response of the process for AISI D2 die steel. Empirical equations were obtained for predicting the performance of the process. Two type of electrodes were used, the copper and graphite electrodes. The results showed that the minimum tensile surface residual stresses obtained when using the copper electrodes with pulse current (22 A) and pulse on duration (120 μs). It is concluded that the use of graphite electrodes and kerosene dielectric alone induced minimum residual stresses with pulse current (22 A) and pulse on duration (40 μs) and with(120 μs) when using the kerosene
dielectric with SiC powder mixing. The copper electrodes with kerosene dielectric alone induced residual stresses about (5%) lower than when using kerosene dielectric with 5g/l SiC powder and about (14%) lower than with graphite electrodes and (8%) when using the kerosene dielectric alone and with SiC powder, respectively.

- by Saad M A H M O O D Ali
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- Pmedm, Silicone carbide powder, Surface residual stresses, Die steel

The powder mixed-EDM (PMEDM) is a prominent field in precise manufacturing where the material removal operation depends on the electrical erosion mechanism between electrodes in this environment. Prior studies strived to improve the performance of this field, but the obstacles represented by controlling the parameters of this environment created difficulties for the researchers. One of the most important results of this situation is the agglomeration problem between the electrode tool and the workpiece that leads to the collapse of the spark. Thus, the performance of PMEDM environment declines. This study covers the primary reasons for the occurrence of the agglomeration phenomenon in PMEDM. In addition, this study proposes a new methodology to compute the quantity of agglomeration through introducing new hypotheses and procedures. Following from here, the proposed methodology is able to determine the dimensions of the recast layer zone and the density of this zone. Energy Dispersive Spectroscopy (EDS) or Optical Emission Spectrometry (OES) plays an important role in specifying the weight percentage of workpiece elements before and after machining in PMEDM. This study adopted a previous study which observed D2 steel before and after machining in PMEDM by using OES. Furthermore, it applies virtual dimensions of the melting area and the recast layer zone for proving this proposed methodology. Therefore, the total agglomeration for D2 steel is 0.003942529 mg while the active agglomeration of tungsten, carbon, molybdenum, and manganese is 0.001971264 mg. Moreover, the square of the correlation factor (R-sq) and R-sq (adj.) resulting from multiple linear regression analysis for the total agglomeration of D2 steel are 99.36% and 98.97%, respectively. Finally, this methodology presents a new mechanism to specify the performance of PMEDM through adopting the agglomeration ratio as a new criterion. Thus, the agglomeration ratio according to the proposed methodology came up to (50%) which implies that the agglomeration did not exceed the critical stage.

- by IAEME Publication
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- EDM, Agglomeration, Pmedm, Recast layer thickness

Electrical discharge machining (EDM) is one of the
most extensively disseminated manufacturing technologies, in
particular as regards the generation of precise and difficult
geometrical shapes on hard metallic components. The objective
of this paper is to Study on Effect of Powder Mixed dielectric in
EDM of Inconel 718. The effect of various powder mixed in
dielectric is studied input parameters like Duty cycles, current,
pulse on time and powder media in that Silicon carbide,
Aluminium oxide, Graphite powder used. Machining
characteristics measured in terms of Material removal rate, tool
wear rate. To obtain the optimal process parameter combination,
optimization is carried out by the Signal-to-Noise (S/N) ratio
analysis of Taguchi method using L18 Orthogonal Array. An
analysis of variance (ANOVA) is used to present the influence of
process parameters on material removal rate, tool wear rate.
Results obtained by Taguchi method and by ANOVA method,
are compared and found that they match closely with each other.
As the MRR is depends mostly on current [4]. Current carrying
capacity of any material depends on it electric conductivity. Here
Graphite is having highest electric conductivity than Aluminium
oxide and Silicon carbide and therefore MRR is higher in case of
Graphite powder. As well as TWR is less.

- by IJSRP Journal
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- Pmedm, Electro Discharge Machining (EDM

This paper deals with studying the effect of powder mixing electrical discharge machining (PMEDM) parameters using copper and graphite electrodes on the white layer thickness (WLT), the total heat flux generated and the fatigue life. Response surface methodology (RSM) was used to plan and design the experimental work matrices for two groups of experiments: for the first EDM group, kerosene dielectric was used alone, whereas the second was treated by adding the SiC micro powders mixing to dielectric fluid (PMEDM). The total heat flux generated and fatigue lives after EDM and PMEDM models were developed by FEM using ANSYS 15.0 software. The graphite electrodes gave a total heat flux higher than copper electrodes by 82.4%, while using the SiC powder and graphite electrodes gave a higher total heat flux than copper electrodes by 91.5%. The lowest WLT values of 5.0 μm and 5.57 μm are reached at a high current and low current with low pulse on time using the copper and graphite electrodes and the SiC powder, respectively. This means that there is an improvement in WLT by 134% and 110%, respectively, when compared with the use of same electrodes and kerosene dielectric alone. The graphite electrodes with PMEDM and SiC powder improved the experimental fatigue safety factor by 7.30% compared with the use of copper electrodes and by 14.61% and 18.61% compared with results using the kerosene dielectric alone with copper and graphite electrodes, respectively.

— Electro discharge machining (EDM) is nontraditional machining process which is used to remove the material by thermal energy of the spark. All electrically conductive materials can be machined. EDM is a capable of machining hard material components or geometrically complex. As there is no direct contact between tool and work piece, no physical cutting forces are present between tool and workpiece. In recent years to enhance process capabilities, powder mixed electric discharge machining (PMEDM) is used as new technique. In PMEDM dielectric fluid is mixed with additive powder. For Experimentation parameters selected are peak current, pulse on time, duty cycle and different dielectric media. Material removal rate, tool wear rate and surface roughness are taken as the output parameter.

The present paper deals with the design of experimental work matrices for two groups of experiments by using Response surface methodology (RSM). The first EDM group was dealt with the use of kerosene dielectric alone, while the second was treated by adding the graphite micro powders mixing to dielectric fluid (PMEDM). The total heat flux generated and fatigue lives after EDM and PMEDM models were developed by FEM using ANSYS 15.0 software. The graphite electrodes gave a total heat flux higher than copper electrodes by (82.4 %). The use of graphite powder and both electrodes yielded more heat flux by (270.1 %) and (102.9 %) than the copper and graphite electrodes, respectively with use of kerosene dielectric alone. Using graphite electrodes and kerosene dielectric alone improved the WLT by (40.0 %) when compared with the use of copper electrodes. Whereas, using copper electrodes and the graphite powder improved the WLT by (66.7 %) compared with the use of graphite electrodes under the same machining conditions. Copper electrodes with graphite powder gave experimental fatigue safety factor higher by (30.38 %) when compared with using graphite electrodes and higher by (15.73%) and (19.77%) when compared with using the copper and graphite electrodes and kerosene dielectric alone, respectively.

In this paper, the effect of silicon powder mixing into the dielectric fluid of EDM on Surface roughness of Al6063 aluminium alloy has been studied. Three process parameters, namely peak current, pulse on time, concentration of powder has been considered. The process performance is measured in terms of surface roughness (SR). The research outcome will identify the important parameters and their effect on SR of Al6063 alloy in the presence of suspended silicon powder in an EDM oil dielectric. The study indicated that all the selected parameters have a significant effect on the mean and variation in SR (S/N ratio). A well-known Taguchi methodology is applied to optimize the SR. The confirmation runs showed that the setting of peak current at a low level (1 A), pulse-on time at a low level (10 ÃŽÂ¼s), powder concentration at a medium level (4 g/l) produced best surface finish from Al6063 alloy surfaces when machined by silicon powder mixed EDM.