Tribological performance in micro-milling of Ti6Al4V under nanofluid-based minimum quantity lubrication

Micromachining processes, derived from scaled-down versions of conventional machining methods, have the potential to meet the growing demand for highly accurate and precise features in various parts. This work aims to explore the effect of distinct nanofluids on the micro-milling performance of Ti6Al4V, considering the size effect and tribological properties of different nanofluids developed indigenously. The cooling and lubrication approaches employed are minimum quantity lubrication (MQL) with Canola oil, nanoemulsion, and carbon nanotubes. Experiments are conducted at differing feed rates to account for the size effect resulting from cutting edge radius. Evaluation of tribological performance includes analysis of thermal conductivity and viscosity of each lubricant, tool wear, and surface morphology of machined slots. The results indicate that canola oil and nanoemulsion yield superior surface finishes at a low feed rate due to their lubricating properties, reducing friction and tool wear. In contrast, a dry environment lacks lubrication, leading to increased friction, tool wear, and a rougher surface finish. Results revealed a reduction in tool diameter by approximately 10–15% for dry conditions, 1–3% for Canola oil, and 3–4% with nanoemulsion. Thus, it can be concluded that MQL confers advantages in enhancing the tribological performance of cutting tools and workpieces during the micro-milling process, promoting sustainability.Graphical Abstract