Influence of Various Cooling and Lubrication Conditions on Tool Wear and Machining Quality in Milling Inconel 718

In recent years the global manufacturing industry has put forward the requirements of sustainable production, as well as a higher demand for product quality and productivity. The ever-increasing environmental requirements require cleaner and more environmentally friendly machining techniques to replace traditional immersion lubrication. Inconel 718 alloy has a wide range of applications in aerospace, chemical and power generation, but the difficult-to-cut nature of this alloy poses a great deal of difficulty in its machining. In this paper, supercritical carbon dioxide (scCO2) based cooling lubrication was used to mill Inconel 718 alloy. The scCO2 technology was combined with the minimal quantity lubrication (MQL) technology and the oil-on-water technology (OoW) technology to quantify the effect of different cooling lubrication by analyzing the milling force, milling temperature, surface roughness and tool wear. The experimental results showed that the use of scCO2-based cooling and lubrication conditions significantly reduced the milling forces and milling temperatures and resulted in better machined surface quality. Lower surface roughness values were obtained with scCO2 + OoW cooling compared to dry milling, only scCO2 cooling and scCO2 + MQL cooling.