Wire Electro Discharge Machining Performance of TiNiCu Shape Memory Alloy

The study presents the effect of Wire Electro Discharge Machining (WEDM) system parameters on the Material Removal Rate (MRR), surface roughness and surface morphology of Ti Ni-50 Cu-45 (5) SMA developed using vacuum arc melting. The WEDM parameters such as pulse on time, peak current, pulse off time and table feed were selected as control factors over MRR and surface roughness. The results reveal that the surface roughness and MRR increases with increased peak current, pulse on time and table feed but decreases slightly with pulse off time. Higher MRR was attained at 5Amps peak current and 70 mu m/s table feed. Better surface roughness was obtained for a combination of lower pulse on time, peak current and table feed with high pulse off time. Surface defects such as recast layer, craters, micro-cracks, pockmarks and voids were found on the machined surface. The globule of appendages formed around the craters and the intensity of the crater was evident for the higher surface roughness with an increase in peak current and pulse-on time during WEDM.