Current research trends in coolant application for machining Ti-6Al-4V alloy: a state-of-the-art review

ABSTRACT Ti-6Al-4 V is one of the α+β type of titanium alloy extensively used in the aerospace industry due to its unique mechanical properties. As a difficult-to-machine material, its cost of processing is very high, which limits its usage. The main objective of this work is to review various cooling techniques used to enhance the machinability of the Ti-6Al-4 V alloy. From the review, it can be revealed that the application of coolants has great implications on machinability concerning chip formation, cutting temperature, cutting force, tool life, surface integrity power consumption, etc. All the cooling methods can enhance the machinability of the Ti-6Al-4 V alloy during various machining operations to a different extent. Implementation of an effective, economical, ecological cooling strategy is a big challenge for modern manufacturing industries. For machining of Ti-6Al-4 V alloy, among all the cooling techniques, cryogenic cooling, solid lubricants, Minimum Quantity Lubrication (MQL)/Minimum Quantity Cooling Lubrication(MQCL), compressed air cooling and nano-fluid with MQL were found effective as well as eco-friendly. Moreover, other than cryogenic all these methods are economical too. Nano-fluid with MQL is a promising technique that needs huge research. This review work can be a base point for further research regarding coolant applications for machining Ti-6Al-4 V alloy.