Abstract:
Theimperative shift toward sustainability has driven contemporary scholars to explore the lubricating and cooling properties of vegetable oils
in traditional metal-cutting processes. Palm oil, as an environmentally conscious derivative, emerges as a preferable option for the base fluid in
Minimum Quantity Lubrication (MQL). However, its high viscosity impedes fluidity, limiting industrial applicability. In contrast, sunflower
oil offers superior lubricating qualities and flowability. Consequently, efforts have been directed toward enhancing the lubricating efficacy of
palm oil. Six blends of palm and sunflower oils (ranging from 1:0.5 to 1:3) were utilized as MQL fluids, followed by evaluations of machining
outcomes, including average surface roughness, specific cutting energy, and tool wear. In addition, an integrated Shannon’s Entropy-based
Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) framework was employed to determine the optimal volume ratio of
the palm–sunflower oil blend. The TOPSIS analysis confirmed that the 1:2 ratio yielded the most favorable outcomes. Subsequent compara
tive analysis demonstrated that this optimal blend resulted in reductions of 16.79% and 14.92% in surface roughness, 11.82% and 10.98% in
specific cutting energy, and 10.19% and 8.45% in tool wear compared to pure palm and sunflower oil media, respectively. Finally, sustain
ability assessments of various cooling media revealed that a minimal quantity of the blended bio-lubricant-based medium outperforms both
compressed air and flooded media.
