Surface integrity of fatigue strength of nickel based super alloy in turning by wire electrical discharge process

In the present work, it is studied how the wire electrical discharge turning factors influence the surface integrity and subsequent fatigue life of Inconel 718. Discharge current, pule on time and spindle speed were taken into account as factors while characteristics to be studied are fatigue life, surface roughness, residual stress, and hardness. It was identified that a sample which is machined by discharge current of 5 A, pulse on time of 600 mu s and work rotational speed of 250 rpm yields maximum fatigue life about 14,400 cycles. After finding the optimum level, statistical models of responses were also generated to correlate input-output relationship as well to identify which parameters has the greatest impact on performance measures. It was found from the results that fatigue life and residual stress is majorly influenced by pules current; while the surface roughness and hardness are significantly affected by spindle speed and pulse o time, respectively.