Sustainability and Efficiency: Comparative Analysis of Vegetable-Based and Synthetic Cutting Fluids in SAE 1045 Steel Turning

The use of mineral oil-based fluids in machining processes can lead to social and environmental problems. Therefore, the objective of this study is to perform a comparative technical-economic analysis between biodegradable emulsions based on babassu oil, castor oil and a commercial synthetic fluid during cylindrical turning of SAE 1045 steel. The formulations' impact on tool wear and durability at varying cutting speeds (90, 70 and 50 m/min) and on the surface roughness of the workpiece was analyzed. Economically, the costs per production volume were compared, using data from the machining tests. The tests demonstrated that the babassu oil-based emulsion provided the longest tool life, reaching 65.31 minutes. The synthetic fluid provided the best surface roughness results. In the economic analysis, the synthetic fluid was advantageous at a speed of 90 m/min, and below this value the castor oil-based emulsion stood out.