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Electrical discharge machining is a promising field of research with wide-ranging application in diverse fields of engineering. With change in demand in the industry, it is very essential to bring about adaptations in the system which would improve the performance of EDM. Electrode used in EDM plays the most vital role in machining. In the review paper, research work related to the manufacturing of electrodes for EDM applications using some innovative methods have been discussed. The manufacture of electrodes has been broadly divided into the following categories: use of casting and machining in electrode manufacturing, use of powder metallurgy in electrode manufacturing, use of rapid prototyping technologies in electrode manufacturing, use of casting and machining for electrode manufacturing. Some suggestions regarding future scope in EDM manufacturing have been made.

A parametric description on surface roughness and sintered density for composites produced via powder metallurgy technique has been given here. This technique has been used to produce composites from low carbon content ferrous powders, which have been taken as matrix, and high carbon content rapidly solidified alloyed ferrous powders, which have been taken as reinforcement. Low carbon content ferrous powders have been annealed at 700 °C for two hours, and high carbon content rapidly solidified alloyed ferrous powders have been annealed at 1000 °C for one hour. These low carbon content ferrous powders and high carbon content rapidly solidified alloyed ferrous powders have been mixed at various weight proportions and compacted at different pressures ranging from 450 MPa to 650 MPa. The compacts have been sintered at three different temperatures like 900 oC, 1000 oC and 1100 °C. The surface roughness and sintered density values have been measured for the sintered compacts at different processing factors. Full factorial design of experimentation has been prepared, and effects of the processing factors on surface roughness and sintered density have been studied using MINITAB 16. Weight percent of high carbon content rapidly solidified alloyed ferrous powders, which has been taken as one of the factors, has been found to be the most significant factor. Its contribution for lowest surface roughness and highest sintered density is the maximum.

The present study highlights a multi-objective optimization problem by applying utility concept coupled with Taguchi method through a case study in electric discharge machining of D2 steel by using electrode produced by direct metal laser sintering (LS). The study aimed at evaluating the best process environment which could simultaneously satisfy multiple requirements such as tool wear rate, material removal rate, and surface roughness. As traditional Taguchi method cannot solve a multi-objective optimization problem, to overcome this limitation, utility theory has been coupled with Taguchi method. Depending on Taguchi’s lower-the-better and higher-the-better criteria, individual response characteristics have been transformed into corresponding utility values. Individual utility values have been added finally to compute overall utility degree which serves as representative objective function for optimization using Taguchi method. The present study combined utility theory and Taguchi method for predicting optimal settings. Optimal result was verified through confirmatory test. This indicates application feasibility of the aforesaid methodology proposed for multi-response optimization and off-line control of multiple quality characteristics in electric discharge machining using electrode produced by direct metal LS.

The present study is aimed at a multi-response optimization problem by applying Principal Component Analysis (PCA) combined with Taguchi method. The investigation has been carried out through a case study in Electric Discharge Machining (EDM) of D2 steel by using copper, brass and Direct Metal Laser Sintered (DMLS) electrode produced by direct metal laser sintering using Directmetal20. The research work has been carried out to evaluate the best parametric combination which could fulfill multiple responses like lower Tool Wear Rate (TWR), higher Material Removal Rate (MRR) and lower Surface Roughness (Ra). Unlike the use of single-objective optimization problem in traditional Taguchi method, a hybrid Taguchi method has been developed in combination with PCA to solve multi-objective problem. Taguchi method assumes that the quality characteristics should be uncorrelated or independent which is not always fulfilled in actual condition. PCA is applied to remove response correlation and to calculate independent (uncorrelated) quality indices known as principal components. These principal components combined with weighted principal component analysis (WPCA) are used to calculate overall quality index denoted as Multi-response Performance Index (MPI). This investigation combines WPCA and Taguchi method for forecasting optimal setting. The predicted result by this method was validated through confirmatory test proving the efficacy of the process. Out of five input process parameters considered, tool electrode has been found to be the most significant factors through the Analysis of Variance (ANOVA).

The present study highlights a multi-objective optimization problem by applying utility concept coupled with Taguchi method through a case study in CNC end milling of UNS C34000 medium leaded brass. The study aimed at evaluating the best process environment which could simultaneously satisfy multiple requirements of surface quality. In view of the fact, the traditional Taguchi method cannot solve a multi-objective optimization problem; to overcome this limitation, utility theory has been coupled with Taguchi method. Depending on Taguchi’s Lower-the-Better (LB) response criteria; individual surface quality characteristics has been transformed into corresponding utility values. Individual utility values have been aggregated finally to compute overall utility degree which serves as representative objective function for optimizing using Taguchi method. Utility theory has been adopted to convert a multi-response optimization problem into a single response optimization problem; in which overall utility degree serves as the representative single objective function for optimization. The study of combined utility theory and Taguchi method for predicting optimal setting. Based on Taguchi’s Signal-to-Noise ratio (S/N), analysis has been made on the overall utility degree and optimal process environment has been selected finally which corresponds to highest S/N Ratio. Optimal result has been verified through confirmatory test. The case study indicates application feasibility of the aforesaid methodology proposed for multiresponse optimization and off-line control of multiple surface quality characteristics in CNC end milling.

The present study highlights a multi-objective optimization problem by applying Weighted Principal Component Analysis (WPCA) coupled with Taguchi method through a case study in cylindrical grinding of UNS C34000 Medium Leaded Brass. The study aimed at evaluating the best process environment which could simultaneously satisfy multiple requirements of surface quality. In view of the fact that traditional Taguchi method fails to solve a multi-objective optimization problem, to overcome this limitation, WPCA has been coupled with Taguchi method. Furthermore, to follow the basic assumption of Taguchi method, i.e., quality attributes should be uncorrelated or independent; which is not always satisfied in practical situation; the study applied WPCA to eliminate response correlation and to evaluate independent or uncorrelated quality indices called principal components which were aggregated by WPCA to compute overall quality index denoted as Multi-Response Performance Index. A combined quality loss was then estimated which was optimized (minimized) finally. The study combined WPCA and Taguchi method for predicting optimal setting. Optimal result was verified through confirmatory test. This indicates application feasibility of the aforesaid methodology proposed for multi-response optimization and off-line control of correlated multiple surface quality characteristics in cylindrical grinding.