Experimental study on the electrical discharge machining with three-phase flow dielectric medium

Abstract

Electrical discharge machining (EDM) with three-phase flow dielectric medium uses gas-liquid-powder mixture as the dielectric medium to improve the machining performance of the EDM. The appropriate selection of processing parameters makes for the improvement of machining properties for this EDM process. The material removal rate (MRR), tool wear rate (TWR), and surface roughness (SR) of EDM with three-phase flow dielectric medium are studied experimentally. The influence of process parameters, including peak current, pulse on time, pulse off time, flow rate, and concentration of powder particles, on these performance parameters, including MRR, TWR, and SR, are found out based on the orthogonal design experiment and the signal-to-noise ratio analysis. The reasons for these influences are analyzed. The optimal combination of process parameters to improve each single performance parameter is obtained. Verification tests are carried out. It is verified that the best combination of process parameters for MRR is powder concentration at the middle level, flow rate at the high level, pulse on time at the middle level, pulse off time at the low level, and peak current at the high level; the best for TWR is powder concentration at the low level, flow rate at the low level, pulse on time at the high level, pulse off time at the low level, and peak current at the low level; the best for Ra is powder concentration at the middle level, flow rate at the high level, pulse on time at the low level, pulse off time at the high level, and peak current at the low level, respectively.