标题：Influence of Flank Face Structuring on Cooling, Tool Lifetime and Borehole Quality When Drilling Inconel 718: Physical Simulations and Experimental Validation
摘要：When drilling difficult-to-cut materials such as Inconel 718, the drills are exposed to high thermomechanical loads. Due to the low thermal conductivity of the workpiece material, a large amount of the generated heat has to be dissipated by the metal working fluid (MWF). However, the cutting zone is located inside the workpiece, which makes it challenging to provide sufficient MWF to the cutting zone. To solve this, drills with internal cooling channels are commonly used. In this work, the influence of differently structured flank faces on cooling efficiency, tool life, process forces and borehole quality is investigated. The influence of the structures on the cooling was investigated by Computational-Fluid-Dynamics (CFD) simulations. These simulations allow a detailed analysis of the flow conditions inside the borehole and showed that the structuring improved flow conditions, especially near the thermally highly loaded main cutting edge. The improved flow conditions resulted in an extension of the tool life by up to 22 % compared to unstructured drills in experimental investigations.
