Study of Film Formation on Grooved Tools in an Atomization-Based Cutting Fluid Delivery System for Titanium Machining

The purpose of this paper is to study the effect of cutting tool surface geometry and the atomization-based cutting fluid (ACF) spray parameters on the characteristics of the thin film formed in an ACF delivery system. A computational model is developed using three submodels that are used to predict the carrier gas flow, droplet trajectories and the film formation, respectively. The model is validated through film thickness measurements using a laser displacement sensor. Turning inserts with chip-breaking grooves along with a conventional flat insert are used to study the effect of cutting tool surface geometry on the model-predicted film characteristics, including film thickness and velocity. Machining experiments are also conducted to investigate the effect of film characteristics on the machining performance in terms of tool wear, which show that the tool wear is minimum at a certain desired film thickness value and large film velocity value. Carrier gas pressure and cutting fluid flow rate are also varied to study the effect of ACF spray parameters on the film characteristics. Increase in the fluid flow results in increase in both film thickness and velocity, while an increase in the gas pressure results in the reduction of the film thickness but an increase in the film velocity.