Authors: Ravinder Kumar; Inderdeep Singh
Addresses: Department of Mechanical and Industrial Engineering, Indian Institute of Technology Roorkee, Uttarakhand, 247667, India ' Department of Mechanical and Industrial Engineering, Indian Institute of Technology Roorkee, Uttarakhand, 247667, India
Abstract: Electric discharge machining (EDM) is gaining significant industrial consideration due to its characteristic of machining difficult to machine materials, irrespective of their hardness. Growing product miniaturisation further extends the application of EDM for the production of components featured with micro cavities. In the present experimental investigation, micro holes were drilled in the copper workpiece using tungsten electrode of diameter 120 μm. Box-Behnken design of response surface methodology was used taking input variables as voltage, feed and tool rotational speed. The performance of the process was evaluated in terms of material removal rates (MRR) and tool wear rates (TWR). Removal rates were calculated based on the volume reduction of workpiece and tool electrode. Analysis of variance (ANOVA) was performed for the significance of the model. The effects of all the input parameters on the responses are discussed. Experimental results show an increasing trend of MRR and TWR with increasing values of voltage and feed rate. Increase of tool rotational speed also has significant effect on MRR and TWR. The multi optimisation of the EDM process parameters was performed and an optimised set of parameters was proposed for the maximisation of MRR and minimisation of TWR.
Keywords: electric discharge machining; EDM; micro holes; material removal rates; MRR; tool wear rates; TWR.
International Journal of Additive and Subtractive Materials Manufacturing, 2017 Vol.1 No.3/4, pp.257 - 264
Received: 20 Apr 2017
Accepted: 29 Sep 2017
Published online: 07 Feb 2018 *