Analysis of electrostatic solid lubricant spray process parameters during turning Ti-6Al-4V alloy

Abstract

Titanium alloys are considered as hard-to-cut material due to its relatively high resistance to corrosion, low thermal conductivity and high chemical reactivity. Effective penetration of sufficient amount of lubricant in the metalworking process is of utmost importance to (a) reduce frictional resistance at the high-temperature tool–workpiece interface and (b) avert the formation of built-up edge in machining process. Traditionally, the lubricant forms a thin fluid film to reduce the friction. In order to reduce or eliminate coolant usage and to apply lubri-coolant efficiently at tool–chip–workpiece interface, a novel near-dry machining technique called electrostatic charged solid lubricant spray system has been developed. In electrostatic charged solid lubricant spray technique, the aerosolized micro-droplet particles were sprayed from the nozzle tip which uses a phenomenon called contact-charge electrification principle. The quick penetration and wettability of charged atomized droplet particles are impinged with high velocity at the tool–chip interface. The focus of the present experimental research is to analyse the optimum lubrication process parameters of the experimental set-up in terms of effectively applying cutting fluid in the machining zone. The study shows that the desired atomization and machining performance of the electrostatic charged solid lubricant spray technique can be obtained by governing different spray parameters (lubricant flow rate, air pressure, spray nozzle position, nozzle distance, electrostatic voltage). The results revealed that when the charged lubricants are applied with high velocity and large number of droplets, it will have significant influence on surface roughness and cutting force. The fabricated electrostatic charged solid lubricant spray technique provides us with an efficient and economic machining solution by applying solid lubricants effectively at tool–material interface during turning of Ti-6Al-4V alloy material. The present approach and the obtained results will help in better understanding of the machinability of hard-to-cut materials in manufacturing industries.

Effect of Various Lubricating Strategies on Machining of Titanium Alloys: A State-of-the-Art Review

“…The sinusoidal texture gave the best result compared to other tools. Gunda et al [56] optimized the machining parameters using the electrostatically charged lubricant spray technique in the turning of Ti-6Al-4V. The cutting force and surface roughness were notably affected by the higher velocity and number of droplets of the charge lubricants.…”

Surface roughness of machined wood and advanced engineering materials and its prediction: A review

“…They turned Ti-6Al-4V and reported that this method efficiently provide solid lubricants and that a large number of droplets and a high spaying speed significantly affected the surface roughness. 60 In addition, the appropriate lubrication for machining is crucial to control the chip-tool-workpiece interface. Gunda et al established an experiment setup to provide high-speed minimum-quantity solid lubricant, and investigated MoS 2 lubricants for turning of Ti-6Al-4V and EN31 alloys.…”

Experimental study on cutting force in ultrasonic vibration-assisted turning of 304 austenitic stainless steel

“…Turning is the most basic, most common and most extensive technical method in the mechanical manufacturing industry, which occupies a very important position in production. 5–8 Extensive use of turning leads many scientific research institutions and production and processing departments to carry on in-depth study on it, meanwhile the development of UAT is also promoted. UAT is different from traditional turning process, which changes from continuous cutting mode of conventional turning (CT) to interrupted cutting and is a typical composite machining method combining ultrasonic vibration with CT. 9–12…”