Investigating the use of soluble oil derived from Magarya nuts as a cutting fluid in machining processes

The growing environmental concerns associated with petroleum based cutting fluids have intensified the search for sustainable and biodegradable alternatives in machining operations. This study investigated the suitability of Magarya nut (Diospyros mespiliformis) oil as an alternative cutting fluid for metal machining applications. Magarya nuts were processed, and the extracted oil was characterized for its physicochemical properties, including density, viscosity, pH, flash point, pour point, acid value, saponification value, moisture content, specific gravity, and thermal conductivity. The results showed that all measured properties fell within ASTM-recommended ranges for cutting fluids, indicating the oil's suitability for machining applications. Machining performance was evaluated using mild steel workpieces under three conditions: dry machining, conventional petroleum-based cutting fluid, and Magarya oil based cutting fluid. The average surface roughness values obtained were 4.81 µm, 2.35 µm, and 2.49 µm for dry machining, petroleum-based fluid, and Magarya oil, respectively. Tool wear was reduced from 0.44 mm under dry machining to 0.19 mm with Magarya oil, while cutting temperature decreased from 83.0°C to 51.6°C. The material removal rate achieved with Magarya oil (245 mm³/min) was comparable to that of the commercial cutting fluid (250 mm³/min). Statistical analysis revealed significant differences among machining conditions (p < 0.05). The findings demonstrate that Magarya nut oil possesses excellent lubrication characteristics, satisfactory cooling performance, and superior environmental sustainability, making it a promising eco-friendly alternative to conventional petroleum-based cutting fluids.