A comparison of cryogenic and high pressure emulsion cooling technologies on tool life and chip morphology in Ti–6Al–4V cutting

The promise of extended tool life or shorter production times with the application of cryogenic coolants and high pressure emulsions during metal machining is encouraging for the widespread commercial adoption of such technologies. Many researchers have previously investigated these coolant technologies in machining and all have reported various benefits. However, until now no direct comparison of each technology has been made using consistent tooling, coolant nozzle position and cutting parameters in titanium turning. This makes industrial adoption difficult because it is still unknown which technology offers superior tool life. This work investigates the tool life and chip morphology during Ti–6Al–4V turning using each coolant with constant cutting parameters and coolant nozzle position. It is found that high pressure water based emulsion offers slightly better tool life than that achievable with cryogenic coolant, however, the most influential parameter is the coolant nozzle position. Several changes to chip morphology were observed with each coolant and these are discussed in-depth.