Although Ti-6Al-4V alloy offers high strength-to-weight ratio, corrosion
resistance, and biocompatibility properties, its machining is challenging due to
low thermal conductivity, high hardness, and chemical reactivity. This study
examines turning of Ti-6Al-4V under minimum quantity lubrication (soybean oil).
Cutting speed (CS), feed rate (FR), and depth of cut (DOC) are considered as the
input parameters. On the other hand, material removal rate (MRR), tool wear rate
(TWR), surface roughness (SR), and cutting force (Fc) are treated as the
responses. Optimization of the said process is carried out using the mixed
aggregation by comprehensive normalization technique (MACONT), a recently
developed multi-criteria decision-making (MCDM) method. The optimal parameters
are identified as CS = 72.26 m/min, FR = 0.022 mm/rev, and DOC = 0.2 mm,
achieving high MRR with low TWR, SR, and Fc. The effects of different turning
parameters on the responses are also investigated. Sensitivity analysis confirms
robustness, and comparative evaluation with other MCDM tools validates accuracy
of the adopted approach. The results demonstrate MACONT’s effectiveness in
optimizing turning of hard-to-machine alloys, supporting greener and sustainable
machining practices.
