Solid Lubricant-assisted Minimum Quantity Lubrication and Cooling strategies to improve Ti6Al4V machinability in finishing turning

The aim of the paper is to test innovative minimal techniques, based on Minimum Quantity Lubrication (MQL) and Minimum Quantity Cooling (MQC) strategies, to improve the tool life and machined product surface quality when applied to finishing turning of difficult-to-cut alloys. Two different MQL and MQC solutions, both based on the addition of Solid Lubricants (SL), were proposed and tested, namely an MQL vegetable oil enriched with PTFE particles and an aqueous solution added with graphite at different percentages. The study proved that the newly developed strategies determined an increase of both the tool life and machined surface integrity, with the best results highlighted for the SL-assisted MQC strategies.