Cutting performance of boron-doped diamond coated tools in drilling of CFRP

This study investigated the effect of boron-doped diamond coated drill on cutting performance when drilling CFRP. The boron-doped diamond coating was deposited on cemented tungsten carbide with cobalt (WC-Co) drills with the hot filament chemical vapor deposition (HFCVD) method, adopting trimethoxyborane as dopant source. The coating characteristics, such as surface morphology and carbon bonds, were investigated by scanning electron microscopy (SEM) and Raman spectroscopy. Drilling tests included tool's flank wear determination, measurement of thrust force and torque. For comparison, the conventional diamond coated and WC-Co drills were also used in the tests. Furthermore, drilled holes were inspected in terms of hole size and delamination. According to the results, boron-doped diamond coated drill showed advantage in tool life and quality of drilled holes over the conventional diamond coated and the WC-Co drills.