Prediction of process parameters using heuristic approach in machining inclined holes by rotating tool electrochemical machining

Electrochemical micromachining (ECMM) creates a geometrical replica of the tool shape on conductive materials when immersed in electrolytes. In this paper, a study on the effect of various tool rotational speeds in ECMM on producing a deep 2 mm inclined (20°) hole on SAE 304 is carried out. Taguchi analysis and ANOVA identified voltage as a significant parameter for metal removal rate (MRR), overcut (OC) and taper angle (TA) at all tool rotational speeds. Fluid flow simulation proves that at 900 rpm, the helix tool rotation can provide better electrolyte replenishment in the machining gap due to which MRR increases. At tool rotational speed of 900 rpm, it was observed an increase in MRR 1.5 times, decrease of OC 2.45 times and TA 1.44 times compared to 300 rpm. A surface integrity study using SEM was carried out to examine the surface walls of the microhole. It was observed that sludges are greatly reduced on the walls of the machined microhole at 900 rpm tool rotational speeds, thereby confirming uniform dissolution. MOGA (Multi objective Genetic algorithm) helps generate many intermediate optimal solutions and MOGA – TOPSIS concludes to have better industrial oriented results than TOPSIS (Technique for Order of Preference by Similarity to Ideal Solution) with less than 2% error deviation. This can be useful for producing industry oriented inclined holes.