Optimization of CNC turning parameters of copper–nickel (Cu–Ni) alloy using VIKOR, MOORA and GRA techniques

Computerized numeric control (CNC) turning is the most widely used machining process for material removal in cylindrical jobs. Cu–Ni alloys have found widespread applications in shipbuilding industries and hydropower plants. While the material's mechanical properties have been proven to be exceptional over the years, optimizing machining parameters becomes crucial to ensure good machinability of the alloy. Multiple Criteria Decision-Making (MCDM) tools are an effective means to identify the best compromise solutions for an optimization problem when conflicting objectives are at play. In the present work, GRA, VIKOR and MOORA techniques have been employed to study the effect of Speed (S), Feed (F), and Depth of Cut (DOC) on Material Removal Rate (MRR) and Surface Roughness (SR) in the turning of Cu–Ni alloys using a carbide cutting tool. The deployment of MCDM techniques indicated the spindle speed of 1500 rpm, feed rate of 0.57 mm/rev and DOC of 1.2 mm as the top-performing input parameters in achieving optimal MRR and SR. The study also suggests that the best compromise is consistently achieved at maximum S, F, and DoC, as indicated by all the MCDM techniques used.