High-throughput electrical discharge milling of WC–8%Co

Abstract

Experiments of high-throughput electrical discharge milling (HTED milling) of WC–8%Co at 600-A peak current and 4766 mm3/min material removal rate (MRR) using a 12-mm-external-diameter and 4-mm-internal-diameter tubular graphite electrode were conducted. The HTED milling process parameters, including peak current, electrode rotation speed, flushing pressure, and peak voltage, were studied to evaluate the effect on MRR, relative electrode wear rate, and diameter of overcut. The cross section, surface morphology, and microhardness of WC–8%Co for HTED milling were also investigated. Peak current has proven to be a critical factor for MRR. The MRR of HTED milling at peak current 600 A can be increased by ten times compared to that of HTED milling at peak current 100 A. Faster electrode rotation speed, larger flushing pressure, and higher peak voltage are essential to achieve low relative electrode wear rate (REWR) and high MRR. This study demonstrates that, using proper HTED milling process parameters and tubular graphite electrode, the HTED milling of WC–8%Co can be processed efficiently.