DROPLET SPRAY BEHAVIOR OF AN ATOMIZATION-BASED CUTTING FLUID (ACF) SYSTEM FOR MACHINING OF TITANIUM ALLOYS

摘要

The aim of this research is to study droplet spray characteristics of an atomization-based cutting fluid (ACF) spray system including droplet entrainment angle and flow development regions with respect to three ACF spray parameters, viz., droplet and gas velocities, and spray distance. ACF spray experiments are performed by varying droplet and gas velocities. The flow development behavior is studied by modeling the droplets entrainment mechanism, and the density and distribution of the droplets across the jet flare. Machining experiments are also performed in order to understand the effect of the droplet spray behavior on the machining performances, viz., tool life/wear, and surface roughness during turning of a titanium alloy, Ti-6A1-4V. Experiments and the modeling of flow development behavior reveal that a higher droplet velocity and a smaller gas velocity result in smaller droplet entrainment angle leading to a gradual and early development of the co-flow with a smaller density and a better distribution of the droplet across the jet flare. Machining experiments also show that a higher droplet velocity, a lower gas velocity and a longer spray distance significantly improve the machining performances such as tool life and wear, and surface finish.