Multi-Attribute Optimization of EDM Drilling Process Parameters on Nitinol Using GRA-Assisted PSO (original) (raw)

2022, 2 nd . International Architectural Sciences and Applications Symposium

Nitinol is an exotic material found its applications in various fields of engineering and medical applications. It is well known for its superior properties like biocompatibility, shape memory effect and superelasticity. On the contrary, it is a difficult-to-cut material due to higher flank wear. Hence, advanced machining processes are best suited for manufacturing Nitinol products. EDM is capable of processing Nitinol. The energy of the sparks leads to material removal through melting and evaporation. Furthermore, the shape-memory effect of Nitinol is temperature-dependent, which requires optimized processing. Therefore, the EDM drilling of Nitinol was carried out using copper electrodes (0.8 mm) and optimized for multiple responses using GRA-assisted PSO. The experimental work was carried out using distilled water as the dielectric fluid. The process parameters considered were the discharge current (I), servo gap voltage (V), discharge time (T ON), charging time (T OFF) and the dielectric flushing pressure (DP). The responses considered for the multi-attribute optimization were material removal rate (MRR), tool wear rate (TWR) and the degree of tapper (DoT). The GRA converted the three-objective problem into a single objective one. The GRG's model was optimized using PSO. The optimized EDM drilling process parameters were I = 22A, V=40 volts, T ON = 6 μs, T OFF = 5 μs and DP = 100 kg/cm 2. The confirmation test was conducted and compared the variations concerning to the predicted ones, and it was found that the MRR, TWR and the DoT varied by 20.9, 27 and 10.9 %, respectively.