MS Shekhawat, Harlal Singh Mali* and APS Rathore Pages 7 - 23 ( 17 )
Aims & Objectives: Producing thin-walled rotationally symmetrical parts of difficult-tomachine materials by electrical discharge machining is an evolving field of research. Poor heat transmissivity, high hot strength and in-process deflection of thin-walledd Inconel 600 parts pose a great challenge for its processing by conventional machining methods.
Methods: In this study, a novel hybrid process called Centreless Electric Discharge Grinding (CEDG) is employed for machining of Inconel 600 tubes using a rotating disc wheel electrode to improve process parameters. This paper details the experimental findings of the influence of four process parameters viz. pulse on time, peak current, gap voltage, and duty cycle on the responses viz. average Material Removal Rate (MRR) and average surface roughness (Ra). Response Surface Method’s (RSM) central composite design was implemented to determine the effects of parameters on responses. Analysis of variance (ANOVA) techniques were employed to establish the adequacy of the mathematical models and to analyze the significance of regression coefficients. RSM’s desirability approach was used to solve the multi-response optimization.
Results: It was clearly noticed that the peak current and gap voltage were the most influential parameters to affect the MRR and surface roughness. Maximum average MRR of 473 mg per min. was achieved at pulse on time 60μs, peak current 25 amps, gap voltage 40 V, at a duty cycle of 8, while minimum average surface roughness of 8.4 μm Ra was obtained at pulse on time 40μs, peak current 15 amps, gap voltage 40 V, and duty cycle 6.
Conclusion: Confirmation run was conducted by adjusting the variables at an optimal level within the selected range. It was concluded that the optimum level of variables can be determined for optimized responses before conducting the experiment.
Centreless electric discharge grinding, thin wall, rotationally symmetric, inconel 600, graphite disc wheel electrode, response surface method’s.
School of Manufacturing Skills, Bhartiya Skill Development University, Jaipur 302042, Department of Mechanical Engineering, Malaviya National Institute of Technology, Jaipur 302017, Department of Mechanical Engineering, Malaviya National Institute of Technology, Jaipur 302017