Industries demand stringent requirements towards economical machining without hindering the surface quality while cutting high carbon high chromium (HcHcr) steel. Electrical discharge machining (EDM) of HcHcr steel aims at reducing machining cost (i.e., maximize material removal rate (MRR) and minimize tool wear rate (TWR)) with good surface quality (i.e., minimize surface roughness (SR)). A comparative study was carried out on EDM of HcHcr D2 steel (DIN EN ISO 4957) by applying Taguchi L18 experimental design considering different electrode materials (copper, graphite, and brass), dielectric fluids (distilled water and kerosene), peak current, and pulse-on-time. The process performances were analyzed with respect to material removal rate, surface roughness, and tool wear rate. Pareto analysis of variance was employed to estimate the significance of the process variables and their optimal levels for achieving lower SR and TWR and higher MRR. Hybrid Taguchi-CRITIC-Utility and Taguchi-PCA-Utility methods were implemented to determine the optimal EDM parameters. Higher MRR of 0.0632 g/min and lower SR of 1.68 µm and TWR of 0.012 g/min was attained by graphite electrode in presence of distilled water as dielectric fluid compared to the brass and copper. Additionally, a metallographic analysis was carried out to study the surface integrity on the machined surfaces. Micrographic analysis of the optimal conditions showed lower surface roughness and fewer imperfections (lesser impression, waviness surface, and micro-cracks) compared to worst conditions.

Experimental analysis and optimization of EDM parameters on HcHcr steel in context with different electrodes and dielectric fluids using hybrid Taguchi-based PCA-Utility and CRITIC-Utility approaches

Grey fuzzy optimization of ultrasonic-assisted EDM process parameters for deburring CFRP composites

This experimental examination exhibit a novel Hybrid Wire electrical discharge machining (H-WEDM) process of ultrasonic vibration combined with traditional Wire-EDM. The metal cutting for form tool and extrusion die with WEDM is liked to give better surface morphology. The effect of residual stresses has been dissected for H-WEDMed machined surface alongside the surface roughness and erosion rate to enhance surface integrity and longer service life of High Carbon High Chromium D2 tool steel. The process parameters chose for this investigation are type of vibration continuous/discontinues, amplitude of vibration, workpiece dimension, duty cycle, peek current and wire feed rate with objective to optimize the residual stresses and erosion rate. Portable X-ray Residual Stress Analyzer, a non-destructive X-ray analyzer is used to measure the residual stress efficiently by detecting the full Debye ring data from a single incident X-ray angle and Non goniometer stage influence on the measurements. An endeavor was made to compare the residual stresses for continuous/discontinues vibration and without vibration. The impacts of amplitude of vibration, peak current, duty cycle and wire feed rate variations on erosion rate was study using Taguchi method. From experimental study, it was observed that discontinuous vibration enhances the erosion rate and diminishes the resultant stresses. High Peak current and duty cycle altogether deteriorate the surface texture, which creates high tensile residual stresses because of debris and micro cracks. The optimum value of residual stresses 86.53 MPa and material erosion rate 6.45 mm/min was achieved using H-WEDM.

Effect of hybrid wire EDM conditions on generation of residual stresses in machining of HCHCr D2 tool steel under ultrasonic vibration

Integrated vibration in electrical discharge machining (EDM) plays a key role in achieving high efficiency. High levels of variables can be employed in this approach due to integration. However, simultaneous optimization of the EDM parameters to achieve multi-objectives is still very complex and challenging. Studies on integrated vibration are still in a preliminary stage. This report addresses multi-objective optimization in EDM for SKD61 die steel using low-frequency vibration. MOORA (Multi-objective optimization based on ratio analysis) was chosen to resolve this multi-objective optimization problem. The material removal rate (MRR), tool wear rate (TWR) and surface roughness (SR) were selected as performance measures in the EDM process. An analytical hierarchical process (AHP) was used to determine the weight value of the quality indicators. The results indicate that low-frequency vibrations significantly improve machining efficiency. When the frequency of the vibrations increased, MRR increased significantly such that MRRMAX = 64.48%. TWR and SR are smaller and their increase are given as TWRMAX = 20.3% and SRMAX = 18.47%. MOORA has been identified as a suitable alternative to multi-objective optimization in an EDM process using low-frequency vibrations for an assigned workpiece. The optimum parameters required to achieve the multi-objective were Ton = 25 μs, I = 8 A, Tof = 5.5 μs and F = 512 Hz, at the resultant quality criteria of MRR = 9.564 mm3/min, TWR = 1.944 mm3/min and SR = 3.24 µm with a maximum error of 8.24%.

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Multi-objective optimization of process parameter in EDM using low-frequency vibration of workpiece assigned for SKD61

https://google.iopscience.iop.org/article/10.1088/2053-1591/ab61b6/pdf

Investigations on weld bead geometry and microstructure in CMT, MIG pulse synergic and MIG welding of AA6061-T6

This paper is an endeavor to comprehend an interactive learning process of ultrasonic vibration assisted Electrical Discharge Machining (USEDM) process performance index. The factors influencing the USEDM process are identified and analyzed, through a logical and systematic framework of graph theory and matrix approach. The interdependency of factors are distinguished and examined. A systematic model of USEDM performance index is proposed to utilize graph theoretic approach (GTA). The performance index for USEDM is obtained so from the matrix model and digraphs to comprehend the power of subjective factors affecting. Factors and sub-factors impacting the performance are perceived and collected into five essential groups e.g. flushing, cavitation, abnormal discharge, dimensional accuracy and surface morphology. GTA framework reveals that the flushing, surface morphology and dimensional accuracy impact the basically ascertains, however cavitation effect can in like manner be unequivocal variables for USEDM performance index regard.

Analyzing and modeling the performance index of ultrasonic vibration assisted EDM using graph theory and matrix approach

In this paper, an attempt has been made to review the literature on strategies formulated and tested in ultrasonic vibration assisted electrical discharge machining (USEDM). The strategies for optimisation of EDM performance include flushing, dimensional accuracy, cavitation, surface morphology, polluted gases and chemical effects etc have been highlighted. The major performance controllable parameters in EDM process have also been discussed in this study. The main emphasis is given on classification of USEDM process on the basis of mode of ultrasonic vibration (UV) action imparted to EDM system, which includes a tool, work piece and the dielectric medium. The ultimate purpose of this study is to generalise the variable relationships of various proposed strategies, which may be applied in industries to improve the performance of USEDM. At the end of this study, some limitations of implementing ultrasonic vibration in EDM have been discussed.

Optimisation strategies in ultrasonic vibration assisted electrical discharge machining: a review

The cellular manufacturing is a well known manufacturing technology that helps to improve manufacturing flexibility and productivity by maximum utilisation of available resources. Cellular manufacturing has been derived as a strong tool for increasing production in batches and job shop production. In cellular manufacturing, similar machines are grouped in machine cells and same processing parts are gathered in part families. Cellular manufacturing systems are those systems which are capable to meet the requirements of modern industries. There are certain enablers which help into the implementation process but also influence each other. The main objective of this paper is to identify and analyse these enablers. In the present work, these enablers have been identified through the questionnaire based literature survey and total interpretive structural modelling approach has been utilised in analysing their mutual interaction.

Sanjay Kumar

Papers

Effect of hybrid wire EDM conditions on generation of residual stresses in machining of HCHCr D2 tool steel under ultrasonic vibration

Analyzing and modeling the performance index of ultrasonic vibration assisted EDM using graph theory and matrix approach

Optimisation strategies in ultrasonic vibration assisted electrical discharge machining: a review

A framework to enhance cellular manufacturing system: a total interpretive structural modelling approach

Simulation of Airfoil Shape for Optimum Wing Characteristics