Keywords: Metal Cutting, Coolant, Flushing Abstract In metal cutting operations the use of different coolants and flushing conditions has a significant influence on the machining performance, process efficiency and environmental phenomena. Using hybrid processes, mainly by superposition of various cooling strategies, offers the potential to extend the existing technological process limits of conventional cutting processes. The paper introduces fundamental simulations and investigation results with various cooling strategies in drilling, turning, grooving and milling such as cryogenic cooling, high-pressure cooling and aerosol dry lubrication. The investigations are conducted on high-temperature alloys with poor machinability. Following the state-of-the-art, high-pressure cooling makes it possible to reliably obtain the highest tool life when machining high‑temperature materials. However, these advantages are mitigated by energy-intensive hardware and the use of cutting fluids that demand considerable cleaning and handling as well as higher costs. Furthermore, follow-up cleaning of workpieces and chips is needed. Consequently, high-pressure cooling is primarily suitable for use during roughing at high material removal rates, since the specific energy consumption can be drastically reduced. In comparison to high-pressure cooling and aerosol dry lubrication, cryogenic cooling by using CO2 or N2 has the better cooling effect due to the lower temperatures when it exits the tool cooling channels. The CO2 characteristics make it possible to integrate this cooling strategy into existing machine systems and modified cutting tools. However, it is more problematic in respect of lubrication, in particular in machining high temperature alloys.
