Experimental investigation and statistical modeling of air-assisted EDM of Al-SiC composite with an improvised tool

The present paper deals with the electrical discharge machining of Al-SiC composite using an air-assisted multi-hole rotary slotted tool. The slot was fabricated on the tool surface to provide easy removal of debris from the inter-electrode gap. The compressed air passed through the multi-hole slotted tool produced a high amount of turbulence and cavitation and directly increased the material removal rate. The influence of process factors such as peak current, tool rotation, discharge air pressure, pulse duration, and duty cycle was investigated by considering them as input parameters with output response, electrode wear ratio and material removal rate (MRR). A comparative analysis of the output response with the solid rotary tool and the air-assisted multi-hole rotary slotted tool was presented. The result shows that the use of the air-assisted multi-hole rotary slotted tool increased the MRR in air-assisted rotary electric discharge drilling (AAEDD) by 40-70%. Moreover, the EWR decreased in AAEDD by 15-25% compared to rotary electric discharge drilling (REDD). The emergence of fewer recast layers and surface cracks in the AAEDD process has been identified compared to the REDD process. A genetic algorithm was utilized to achieve optimal process factors by optimizing the AAEDD for maximizing the MRR and minimizing the EWR.