Tool wear and machined surface characteristics in side milling Ti6Al4V under dry and supercritical CO2 with MQL conditions

摘要

Ti6Al4V alloy is a typical difficult-to-cut material. In order to improve its machinability and realize cleaner production, eco-friendly cooling/lubrication techniques are applied. Therefore, this study aims to investigate the tool wear, surface topography, cutting torque, and surface profile in side milling Ti6Al4V under four sustainable conditions, i.e., dry, supercritical carbon dioxide (scCO(2)), scCO(2) with antifreeze water based minimum quantity lubrication (scCO(2)-WMQL), and scCO(2) with oil-on-water based MQL (scCO(2)-OoWMQL) conditions. A theoretical model of flank wear width VB with average prediction error 15.87% is established. scCO(2)-OoWMQL reduces VB by 67.2% compared to scCO(2) alone due to improved lubricity. Detailed characteristics of machined surface profile are investigated using continuous wavelet transform. The performance of scCO(2)-OoWMQL as a new sustainable and efficient cooling/lubrication technique is superior to scCO(2) alone.