Study of Droplet Spray Behavior of an Atomization-Based Cutting Fluid Spray System for Machining Titanium Alloys

Abstract

The atomization-based cutting fluid (ACE) spray system has been found to be effective for improving the tool life and overall productivity during the machining of titanium alloys like TÍ-6AI-4 V. The aim of this research is to study droplet spray characteristics of an ACE spray system including droplet entrainment zone (e.g., angle and distance) and droplet-gas co-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. Machining experiments are performed in order to understand the effect of the droplet spray behavior on the machining performance, viz., tool life/wear, and surface roughness during turning of a titanium alloy, TÍ-6AI-4 V. The flow development behavior with respect to the spray distance is studied by modeling the droplets entrainment mechanism. The model is validated by the ACF spray experiments. 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, and a better distribution of the droplets across the jet flare. Machining experiments also show that a higher droplet velocity, a lower gas velocity and a longer spray distance significantly improve tool life and surface finish.

A Thermal Model to Predict Tool Temperature in Machining of Ti–6Al–4V Alloy With an Atomization-Based Cutting Fluid Spray System

“…Furthermore, the spray used in this work is a low-dense spray. This is justified by the experimental observations of spray characteristics by Nath et al [3] under similar experimental conditions as carried out in this work. The spray angle was reported to be in the range of 36.9-46.66 C. The corresponding diameter of spray cross section at a spray length of 55 mm can be obtained as 36.69-47.44 mm.…”

“…However, for a microscopic droplet and a low dense spray, the proposed model would be perfectly applicable as is the case in ACF spray system. Table 3 Properties of fluid [1] q l (kg/m 3 ) 1003 Figure 14 shows the temperature profile of the tool from the cutting edge for different spray and cutting conditions. It is observed that the tool temperature at the cutting edge is as high as 1200 C for dry cutting at a feed-rate of 0.2 mm/rev and speed of 80 m/min.…”

“…In comparison to other cooling techniques such as highpressure cooling and cryogenic cooling, ACF spray system uses much less energy, thus making it energy efficient. Initial studies by Hoyne et al [1,2] and Nath et al [3] have reported that the ACF spray system improves machining performances including tool life and reduced temperature in turning of Ti-alloys. The process is known to involve several complex phenomena such as droplet-surface interaction and film formation [1], which are influenced by cutting fluid and spray characteristics, viz., droplet size, droplet diameter, and droplet velocity.…”

Investigation of the effects of cryogenic machining on surface integrity in CNC end milling of Ti–6Al–4V titanium alloy

“…Conversely, aerospace and medical original equipment manufacturers (OMEs) have defined requirements in terms of surface finish and the use of specific types of cutting fluids which does not allow complete abandonment of cutting fluids in machining components from advanced alloys. Ti-6Al-4V titanium alloy is one of the most attractive materials in aerospace and medical industries owing to its high specific strength, hardness, corrosion resistance and biocompatibility [5,6]. Ti-6Al-4V α-β titanium alloy is known to be the most used type of titanium alloy accounting for more than 50% of global production with 80% of this being used in aerospace and medical industries [7].…”

Effect of Process Parameters on Surface Roughness in HPC Drilling of AISI 1055 Steel

“…High pressure cooling, cryogenic cooling [1,2] and atomized coolant spray [3,4] are the most focused trends in the manufacturing research [5].Various researchers have studied the high-pressure coolant machining. Lopez de Lacalle et al [6] studied the influence of HPC in drilling of Inconel 718 and Ti6A14V.…”