Performance evaluation of TiN-coated twist drills using force measurement and microscopy

Abstract In the present investigation, the performance of TiN-coated M2 high speed steel drills has been systematically evaluated by drilling a plain carbon steel workpiece. Tests were also performed with uncoated drills for comparison purposes. During the course of testing torque and thrust forces were recorded continuously. A scanning electron microscope was used to elucidate the possible wear mechanisms of worn drills. These studies indicate that various modes of wear are operative in the coated and uncoated tools. The effects of the surface finish and geometry are discussed in the broader perspective of quality assurance needs for coated tools.