Analysis of high speed drilling AISI 304 under MQL condition through a novel tool wear measurement method and surface integrity studies

Drilling of SS 304 under dry, flood, and MQL at a relatively high cutting speed of 90 m/min and feed of 525 mm/min is studied. A novel flank wear measurement method is developed for accurate measurement of total drill flank wear - as the sum of the conventional flank wear width and the material lost due to erosion of the cutting edges. Comprehensive surface integrity analysis for machining under such “high speed” – micro-hardness, local plastic deformation on the hole wall surface, surface roughness, and surface irregularities, exit burr - is reported for the first time. The presence of “piercing” type material removal near the drill exit is revealed for dry and flood machining. The tool life, cutting force, drilled hole diameter error, and chip morphology are also analyzed. MQL produces a machining performance often exceeding that of flood lubrication with respect to several machinability parameters considered in this study. [Display omitted] •High-speed drilling of AISI 304 at 90 m/min and 525 mm/min feed is studied under dry, flood, and MQL conditions.•A novel tool wear measurement method is developed to accurately determine abrasion and material loss (erosion) along the cutting edge.•Comprehensive analysis of surface integrity - micro-hardness, microstructure, and roughness - of the drilled hole is done.•The occurrence of “piercing” like material removal near drill exit for dry and flood lubrication is identified.•Chip morphology and BUE on the drill cutting edges under different lubrication conditions is studied.