Modeling of kerf width and surface roughness in wire cut electric discharge machining of Ti-6Al-4V

Abstract

Surface roughness and kerf width are the two challenging quality characteristics in wire cut electric discharge machining (WEDM) of Ti-6Al-4V to improve accuracy in machining. In this study, effect of wire displacement on the kerf width and surface roughness is studied in WEDM of Ti-6Al-4V. Mechanistic models are developed for kerf width and surface roughness using amplitude and frequency of wire vibration in X and Y directions. Amplitude and frequency of wire displacement in X and Y directions are directly measured using an accelerometer at different working conditions. The estimated kerf width and surface roughness are compared with the experimental results and the average error between them is found to be 3.7 and 4.2% respectively. The results showed that the current and wire tension have significant effect on the wire displacement. The kerf width and surface roughness are effected more by the applied current and the metal removal rate is effected by current and pulse on time. A working condition with 3.3 A of current, 15 N of wire tension, 14.4 µs of pulse on time and 41.5 µs of pulse off time is found to be an optimum working condition.