Kerf-width optimization and surface characterization of wire electric discharge machined Ti-6Al-4V using response surface method

Wire-Electric Discharge Machining (WEDM) is one of practicable advanced machining techniques for machining of hard materials such as Titanium alloys precisely. It is critical to optimize the settings for control parameters to achieve the desired levels of kerf width and dimensional tolerance. Considering this objective, this research investigates the effects of current, pulse on time (T_on) and pulse off time (T_off) on kerf width of Wire-Electric Discharge (WED) machined Ti-6Al-4V Titanium alloy. The study showed that, increase in current from 2 A to 6 A resulted in increase of kerf width by 9.34% and 12.62%, respectively. But increase of T_off from 20 μs to 30 μs led to a sharp reduction in kerf width by about 6.14%. Further, a regression model is developed to predict the surface roughness with coefficient of determination (R²) =90. 11%. The machi ned surfaces are characterised by the presence of voids and microcracks on the recast layers, formation of micro-globules, ridges and craters due to thermal effects. Within the range of study T_off showed significantly larger influence in minimizing the kerf width compared to other parameters of the study.