High-pressure coolant on flank and rake surfaces of tool in turning of Ti-6Al-4V: investigations on surface roughness and tool wear

In this work, the surface quality and tool behavior have been investigated. The experiment was conducted by turning Ti-6Al-4V alloy using coated carbide tool wherein the cutting conditions were dry and high-pressure coolant (HPC). Using specially designed nozzle system, the pressurized coolant was directed towards the rake and flank surfaces of the tool. The quality of the machined surfaces was examined in respect of different cutting speed and feed rate, whereas the tool life (and wear) was determined in terms of machining time. Moreover, the tool wear was scrutinized by scanning electronic microscopic (SEM) images of the worn out inserts. The improvement of surface finish, achieved as result, by HPC is attributed to the effective cooling and lubrication, low-material adhesion, reduced chip rubbing, and elimination of built-up edge. Furthermore, the applied coolant prolonged tool life by approximately 40 %. SEM images revealed that the crater and notch wear in dry cutting whilst exorbitant rubbing over rake and abrasion on flank surface in HPC-assisted turning were the dominant wear mechanisms. Overall, the HPC with double jets is found suitable for turning titanium alloy in respect of surface finish and tool performance.