Title: Effects of powder mixed dielectric on electro discharge machining (PMEDM) of HSS tool steel
Authors: Harshad A. Sonawane; Raju S. Pawade
Addresses: Department of Mechanical Engineering, Dr. Babasaheb Ambedkar Technological University, Lonere 402 103 MS, India. ' Department of Mechanical Engineering, Dr. Babasaheb Ambedkar Technological University, Lonere 402 103 MS, India
Abstract: This paper reports the effects of fine powder suspended dielectric fluid on machinability of HSS tool steel in electro discharge machining. The machinability has been assessed in terms of material removal rate (MRR), relative wear ratio (RWR) and surface roughness (SR) as the response variables. The experiments were designed considering seven input factors viz. polarity, electrode type, pulse current, pulse time, gap voltage, duty cycle, and powder type. Taguchi orthogonal array L18 was used. Analysis of results indicates that the graphite powder mixed dielectric is found influential on MRR and RWR, whereas silicon powder mixed dielectric produced lower surface roughness. Based on the GRA multi-objective optimisation, the PMEDM process set at 20 amp pulse current, 90 volts gap voltage, 200 sec pulse duration and 4% duty cycle with silicon powder added electrolyte, aluminium electrode with positive polarity produce the component with lower surface roughness and RWR and higher MRR.
Keywords: HSS; high speed steel; tool steel; powder mixed dielectric fluids; material removal rate; MRR; relative wear ratio; RWR; surface roughness; surface quality; electro-discharge machining; electrical discharge machining; EDM; Taguchi methods; orthogonal arrays; grey relational analysis; GRA.
International Journal of Mechatronics and Manufacturing Systems, 2012 Vol.5 No.5/6, pp.431 - 454
Received: 12 Jul 2011
Accepted: 22 Jan 2012
Published online: 21 Aug 2014 *