Electric discharge drilling with gas-assisted multi-hole slotted tool

Abstract

This paper proposes the use of a novel electrode containing a modified design intended to promote gas-assisted tool rotation-induced debris removal. The proposed tool was observed to be efficient in dispensing the accumulation of eroded materials from the discharge gaps. In this, study the influence of process parameters like discharge current, tool speed, gas pressure, pulse duration, and duty cycle on output responses is investigated. This outputs responses include: Material Removal Rate (MRR), Electrode Wear Ratio (EWR), and Surface Roughness (SR). A comparative study of the output responses was made with a solid rotary tool and the gas-aided multi-hole slotted tool. The outcome revealed that the application of the multi-hole slotted tool increased the MRR in Air-Aided Electric Discharge Drilling (AAEDD) by 40-80%. Besides this, the EWR decreased in AAEDD by 17-25% compared to rotary electric discharge Drilling (REDD). Moreover, the SR of the AAEDD process was comparatively higher (9-15%) than that of the REDD process. The findings showed less surface crack, micropores and recast layers on specimens machined by the AAEDD process in comparison to the REDD process. This study proposes a novel method for improving the machining performance by improving the flushing efficiency of the machining gap to improve the material removal mechanism.