Performance of micro-drilling of hard Ni alloys using coated and uncoated WC/Co bits

Abstract

An investigation was conducted into the process of microscale hole drilling, in which commercially available uncoated and TiAlN coated WC/Co drill bits were used for microhole drilling in the Ni-based superalloy Inconel X-750. The life of the drill bits, quality of holes drilled, and the mode of drill bit damage during the machining process were evaluated. In all experiments conducted, wear on the drill bit flute face was not observed and flank face wear was observed instead. Significant adhesive attachment of the workpiece material onto the drill bit was observed on both uncoated and TiAlN coated drill bits. The progression of drill bit damage and the impact of the TiAlN coating on drill bit life and hole quality are discussed.