Electrochemical arc micro-drilling of Nickel-Titanium SMAs utilizing GRA-based AHP and RSM

Abstract

Electrochemical arc machining (ECAM) is a hybrid technique which is discovered by the further development of ECDM. As Nickel-Titanium is a hard-to-cut shape memory alloy, therefore ECAM has been utilized. For any manufacturing industry, the machining characteristics are an essential component of the process for the production of NiTi-based things, therefore in this study, MRR, TWR, over cut, and delamination have been chosen as performance parameters whereas voltage, electrolyte concentration (ethanol with ethylene glycol and NaCl), and tool rotation has been selected as variable parameters. The molybdenum has a low tendency to react chemically, therefore it was chosen as a tool for drilling NiTi. The optimum drilling condition has been detected as 20 v/v% of electrolyte concentration, 0 rpm of tool rotation, and 80V of voltage with help of the GRA-based AHP technique, and further, the GRG was optimized by RSM. The optimum value of the performance parameter has been observed as 101.19 mg/min, 0.006 mg/min, 0.111, and 1.16 for MRR, TWR, OC, and delamination respectively. The SEM analysis revealed HAZ, a white layer, melted droplet, number of cavities, craters, and microvoids near the drilled hole. Furthermore, EDX analysis proved that the work surface can be free of Mo after machining Nitinol by electrochemical arc machining. Also, the XRD analysis revealed the development of carbides like TiC in the melting zone of a drilled hole, where that carbide can vanish the shape memory properties in HAZ. As the electrolyte used is a water-free electrolyte, therefore no formation of oxides was observed.