Drilling performance of micro textured tools under dry, wet and MQL condition

In metal cutting processes, reduction in sliding friction at the cutting regime can improve the machining performances in terms of cutting force reduction, built-up edge stabilization and improved surface integrity. However in drilling, as the cutting action occurs inside the hole, minimization of frictional effect at the contact interfaces is always a challenging task, as the reachability of cutting fluids at the machining zone is obstructed by the upward motion of chips sliding along the flute surface. This challenge can be addressed by functionalizing the drill tool surfaces with microtextures. Hence, in the present work, a novel drill tool having microtextures at the flute and margin side is used to reduce the sliding friction. The performance evaluation of microtextured drill tool was done based on the variation in thrust and torque. Margin textured tool was found to be more efficient than flute textured and non-textured tool recording a net thrust force reduction of 10-12% in dry, 15-20% in wet and 15-19% in MQL condition. Reduction in contact length, wear debris entrapment and formation of micropool lubrication effect at the cutting regime are found to be the underlying mechanisms responsible for the improved performance of microtextured drill tools.