Tribological behaviour of Ti6Al4V and Inconel718 under dry and cryogenic conditions—Application to the context of machining with carbide tools

This paper aims at improving the understanding of cryogenic assistance in machining Ti6Al4V and Inconel718 with carbide tools. It especially intends to investigate the cooling and/or lubrication capabilities of a nitrogen jet under extreme contact conditions using a dedicated tribometer. Whereas neither liquid nor gas nitrogen is able to decrease friction coefficient and adhesion on Ti6Al4V, it is proved to be efficient on Inconel718 with a prevailing effect of the liquid phase. In both cases, applying gas nitrogen already decreases the amount of heat transmitted to the pin but this can be drastically enhanced by using liquid nitrogen. Finally, this work provides quantitative data regarding friction coefficient under dry and cryogenic conditions that can be implemented in numerical cutting models.