Environmental and technical evaluation of Babassu and Sunflower oils as cutting fluids for precision drilling in Al-Mg-Si alloys

The increasing global concern with environmental preservation and its impacts on society has driven significant changes in manufacturing processes, many of which are still responsible for pollution. To sustainably meet the growing demand for high-quality products, industries have adopted new environmentally responsible technologies and methodologies. In this context, the pursuit of sustainable alternatives in manufacturing has become essential. Among these, clean drilling of aluminum alloys has gained considerable attention, particularly in sectors where precision and quality are vital to competitiveness. This study conducts a comparative evaluation between a conventional synthetic-based cutting fluid, specifically designed for aluminum machining and two vegetable-based fluids (Babassu oil and Sunflower oil) during constant-pressure drilling of Al6351-T6 aluminum alloy. All fluids were applied using Minimum Quantity Lubrication (MQL). Dry machining tests were also performed. Output parameters included drilling depth, cutting power and chip thickness. The results demonstrated that the vegetable oils were effective and exhibited performance comparable to the commercial cutting fluid. Cutting power was primarily influenced by rotation speed, increasing with higher spindle speeds, while applied load did not significantly affect this variable. Drilling depth was directly affected by both the cutting fluids and operational parameters, with better outcomes observed under lubricated conditions, particularly when using the Quimatic fluid.