Impact of supply conditions of liquid nitrogen on tool wear and surface integrity when machining the Ti-6Al-4V titanium alloy

Abstract

Cryogenic-assisted machining has already shown its advantages on the process and the machining parameters have been analysed. However, part of the coolant jet characteristics as the pressure and flow rate have not been completely studied and optimized. Hence, the main objective of this study is to investigate the impact of these parameters on tool wear and surface integrity when machining the titanium alloy Ti-6Al-4V. Several nozzle diameters have been therefore employed in order to vary the pressure and the flow rate. A new nozzle holder has been developed to ensure the replacement of these calibrated nozzles of different diameters. The machining tests have allowed to draw attention to the impact of the pressure and the flow rate oftheliquid nitrogenjet not only ontool life but also on surface integrity. Indeed, the increase of flow rate and pressure increases tool life. Moreover, surface integrity has been greatly improved notably atthe highest pressure and the highest flow rate.