Hybrid cooling-lubrication in milling Inconel 718: scCO 2 -Assisted MQL and OoW performance

作者：Tianci Gui, Heng Zhang, Nianfeng Zhang, Kai Zhang · 发表于：Materials and Manufacturing Processes · 年份：2025 · DOI：10.1080/10426914.2025.2535309 · 被引用次数：7 · 研究领域：Advanced machining processes and optimization、Injection Molding Process and Properties、Advanced Machining and Optimization Techniques

Inconel 718 is widely used in aerospace and automotive industries due to its superior mechanical and thermal properties, yet its low thermal conductivity and work-hardening behavior lead to rapid tool wear during machining. This study evaluates two hybrid cooling-lubrication strategies-supercritical CO2 (scCO2) combined with Minimum Quantity Lubrication (MQL) and Oil-on-Water (OoW)-in the milling of Inconel 718 using PVD-TiAlN-coated tools. Cutting force, friction behavior, and tool wear mechanisms were systematically analyzed. Results show that, under the most effective parameters observed, both scCO2+MQL and scCO2+OoW reduce cutting forces by over 10% compared to dry machining. MQL exhibits superior frictional performance owing to its high wettability, while OoW provides a balanced synergy between cooling and lubrication. SEM and EDS analyses reveal that coating delamination, material adhesion, and substrate exposure are the dominant wear mechanisms. The synergistic effect of scCO2-assisted lubrication greatly mitigates tool wear and enhances surface quality.