Experimental exploration and optimization of dual-channel electrode micro-drilling in Inconel 617 using electrical discharge machining

This article details the micro deep hole drilling of Inconel 617 superalloy using electrical discharge machining employing a dual-channel copper electrode. Drill speed, tool erosion rate, surface roughness, aspect ratio and dimensional aspects of the drilled holes such as overcut, taper angle, etc., have been investigated. The micro machining process parameters included in the analysis are voltage, current, pulse on/off time and retraction duration. Analysis of the process is done using two latest heuristic optimization techniques, namely Transit Search and Jaya algorithm. The results of these algorithms are detailed and compared to determine the most apt algorithm for this machining study. Further microstructural investigations of the drilled holes are also detailed to comprehend the materials behaviour and the extent of surface damage during such micro-drilling process.