Experimental investigation on electro-discharge surface modification phenomenon of P20+Ni die steel using green P/M composite electrode

Abstract

In the present work, attempts have been made to optimize the EDM process with an aspect of surface modification of AISI P20+Ni die steel using powder metallurgy (P/M) electrode. Experiments have been performed according to central composite rotatable (CCD) design using response surface methodology (RSM). Effects of compaction pressure (Cp), peak current (Ip), pulse-on time (Ton), and duty cycle (τ) were correlated with surface roughness (SR) and microhardness (MH). Adequacy of mathematical model has been checked by performing ANOVA. Composite desirability approach was used to obtain optimal set of parameters for minimum SR and maximum MH. The errors between the predicted and experimental value of responses at the optimal set of parameters for SR and MH maintain within 5.26% and -3.64% respectively. Scanning electron microscope and energy dispersive spectroscopy analysis confirmed the transfer of P/M electrode material on the work surface. The result indicates three times improvement in microhardness of EDMed surface.

Keywords

• edm
• p/m composite electrode
• response surface methodology (rsm)
• surface roughness (sr)
• microhardness (mh)
• composite desirability