Machinability of ultrasonic-stir-squeeze cast A356/ZrO 2 /GO hybrid nanocomposite under sustainable MQL condition

This study involves the fabrication of a novel ultrasonically enabled stir-squeeze cast Al356/0.5 wt.% GO/1 wt.% ZrO₂ hybrid nanocomposite with uniform distribution and investigates sustainable MQL precision turning using rice bran vegetable oil. The primary wear mechanisms identified include abrasion from hard reinforcements, adhesion resulting from the transfer or adherence of work material, and diffusion caused by elevated cutting temperatures through atomic migration and built-up edge (BUE). Depth of cut influences more on flank wear with 74.12%, cutting speed on surface roughness and cutting power with 80.12%, 76.9% and depth of cut and cutting speed on Ne with 48.44% and 47.08% contribution with segmented saw tooth formation. Utilizing COPRAS, optimal parameters are depth of cut of 0.1 mm; feed of 0.06 mm/rev, and cutting speed of 90 m/min. Tool life is 38.1 minutes at optimal run where circularity deviation is greatly reduced, i.e., 0.029, and total machining cost per cut is Rs. 52.21 only. An increase in energy and carbon footprint savings per annum, i.e., 21.65% and 22.11 kgCO₂/kWh, occurred which enhances economic and ecological advantages toward sustainability.