EFFECT OF MICRO SCALE TEXTURES ON DRILLING PERFORMANCE OF CARBIDE TOOLS IN DRY AND WET MACHINING OF TI-6AL-4V

Surface textures helps in controlling the tribological, optical, mechanical, and thermal properties on the surfaces. The recent advancements in precision machining, makes it possible to generate micro/nano patterns on the surfaces with high dimensional control. In the present work an attempt has been made to reduce the thrust force and torque developed during drilling super alloy, Ti-6A1-4V by creating micro dimples on the tool surfaces. Circular dimples having an average diameter of 35 micrometer were created on the flute and margin side of the drill bit using Nd:YAG laser. Scanning electron microscopy analysis has been done to evaluate the quality of generated micro dimples. Drilling experiments were carried out on the titanium alloy in both dry and wet conditions using flute textured, margin textured and non textured tool for understanding the effect of micro textures on the tool. From the force analysis it was observed that in both dry and wet conditions there was a considerable reduction in thrust force and torque. Surface inspections of the drill bit were performed using Stereomicroscope for investigating the titanium buildup on the cutting tool surfaces. Results showed that the margin textured tool performed better than the flute textured and untextured tool in both dry and wet conditions.