Optimization in Wire Electric Discharge Machining of Nickel -Titanium Shape Memory Alloy

The present study focuses on optimizing the process parameters during machining of NiTi (Nickel-Titanium) shape memory alloy by wire electric discharge machining (Wire EDM) for simultaneously maximizing material removal rate and minimizing tool wear rate using brass wire as electrode. Taguchi's design with utility and modified utility optimization techniques have been used for simultaneous multi-response optimization. Different analyses were performed to determine the optimal settings in both utility and modified utility concepts. The optimal results of both methods disclose that the pulse on time of 115 mu sec and pulse off time of 40 mu sec with spark gap set voltage of 20V are useful for maximizing material removal rate and minimizing tool wear rate. The optimization results indicate that the spark gap set voltage is the majority significant parameter that affects the tool wear rate and material removal rate.