Sustainable Cooling and Lubrication Strategies in Machining: Advances, Performance, and Future Perspectives

Demiral M., KÖKLÜ U.

INTERNATIONAL JOURNAL OF PRECISION ENGINEERING AND MANUFACTURING, 2026 (SCI-Expanded, Scopus)

Özet

The growing demand for high-performance machining of advanced and difficult-to-cut materials, combined with stricter environmental regulations and sustainability targets, has driven a fundamental shift from conventional flood cooling toward more sustainable cooling and lubrication strategies. Although effective in heat removal, flood cooling involves high fluid consumption, significant environmental burden, operator health risks, and substantial disposal costs, motivating the adoption of alternatives such as minimum quantity lubrication (MQL), cryogenic cooling using liquid nitrogen (LN2) or carbon dioxide (CO2), and hybrid cooling-lubrication systems. This review provides a comprehensive and critical synthesis of recent developments in sustainable machining, examining their fundamental mechanisms, performance benefits, and industrial relevance. The paper compares the effectiveness of MQL, cryogenic, hybrid, and nanoparticle-enhanced approaches across metallic alloys, metal matrix composites, and fiber-reinforced polymers, with particular attention to cutting forces, temperature control, tool wear, surface integrity, chip formation, energy efficiency, and environmental impact. Recent advances in process modeling, optimization, and data-driven methods are also assessed, highlighting both their potential and current limitations. Practical challenges related to fluid delivery, nozzle design, cryogen logistics, nanofluid stability, scalability, and occupational safety are critically discussed to bridge the gap between laboratory research and industrial implementation. Finally, key research gaps and future directions are identified to support the transition toward reliable, scalable, and truly sustainable machining systems.