Surface texturing of drill bits for adhesion reduction and tool life enhancement

Properly designed micro-scale surface textures can have positive impact on adhesion reduction and lubrication enhancement, which can lead to lower friction and improved performance of a contact interface. The present study aims to utilize this function of textures to reduce the adhesion between a drill and a workpiece. In this study, rectangular surface textures were generated on the margins of drill bits using a diode-pumped Nd:YVO₄ picosecond laser with a wavelength of 532 nm. Two designs were created in which the textures covered approximately 10 and 20 % of the margin surface area. Textured drills were tested by drilling a series of holes in a titanium plate while recording cutting forces, and the results were compared with the performance of baseline samples. Thermographic heat profiles and visual inspections of the drills were taken at increments of 5 and 10-15 holes, respectively. The comparison demonstrated an encouraging improvement in drill bit life as judged by the number of holes drilled before failure. Textured drills were found to reduce adhesion of titanium chips on the drill margins. This work has demonstrated the potential of texturing to significantly improve the lifetime of drill bits and similar cutting tools.