Performance and Surface Alloying Characteristics of Cu-Cr and Cu-Mo Powder Metal Tool Electrodes in Electrical Discharge Machining

Abstract

The main objective of this study is to investigate the effect of Cu-Cr and Cu-Mo powder metal (PM) tool electrodes on electrical discharge machining (EDM) performance outputs. The EDM performance measures used in the study are material removal rate (MRR), tool electrode wear rate (EWR), average workpiece surface roughness (R-a), machined workpiece surface hardness, abrasive wear resistance, corrosion resistance, and workpiece alloyed layer depth and composition. The EDM performance of Cu-Cr and Cu-Mo PM electrodes produced at three different mixing ratios (15, 25, and 35wt% Cr or Mo), compacting pressures (P-c = 600, 700, and 800MPa), and sintering temperatures (T-s = 800, 850, and 900 degrees C) are compared with those machined with electrolytic Cu and Cu PM electrodes when machining SAE 1040 steel workpiece. Analyses revealed that tool materials were deposited as a layer over the work surface yielding high surface hardness, strong abrasion, and corrosion resistance. Moreover, the mixing ratio, P-c, and T-s affect the MRR, EWR, and R-a values.