Optimisation of WEDM parameters on Nitinol alloy using RSM and desirability approach

Machining of Nitinol alloy is complicated by the traditional process due to severe strain hardening and low thermal conductivity, which prompts high tool wear and indigent surface quality. Wire Electro Discharge Machining (WEDM) has been most commonly used for machining Nitinol alloy. In this paper, the effect of input attributes such as pulse on time (T-on), pulse off time (T-off), peak current (I-peak) and voltage (V) on metal removal rate (MRR) and surface roughness (SR) during WEDM of Nitinol alloy have been investigated. Experiments were conducted according to central composite design (CCD) of response surface methodology (RSM). Analysis of variance (ANOVA) was used for studying the effect of input attributes and their interactions. It is perceived that at smaller values, T-on and I-peak are more significant attributes for improving the MRR and surface finish. The optimum conditions are obtained for minimising surface roughness and maximising MRR using RSM and Desirability analysis. Confirmation test was conducted with optimum input attributes where the estimated values of the output attributes were contrasted with the experimental results. It was established that the experimental and the estimated values are in very close agreement.

Automated summary

The study investigated the effect of input attributes on metal removal rate and surface roughness during WEDM of Nitinol alloy, finding that pulse on time and peak current play a significant role in improving machining efficiency and surface quality. Optimum machining conditions were obtained using response surface methodology, with experimental results closely matching theoretical values.