Effect of Grain Size of CVD Diamond Film on Cutting Performance of Diamond Coated Micro Drills

摘要

In this study, micro- crystalline diamond(MCD), fine grade diamond(FGD) and nano-crystalline diamond(NCD) thin films are successfully coated on WC-Co micro drills(φ=400nm) adopting hot filament chemical vapor deposition (HFCVD) technique. The microstructure and cutting performance of micro drills for applying to drill electrical discharge machining(EDM) graphite coated with MCD, FGD and NCD films are systematically investigated by means of field emission scanning electron microscope(FESEM) and Raman spectroscopy. After drilling of 1500 holes, wear behavior of these micro drills is analyzed by FESEM and NCD coated micro drills exhibit minimum flank wear compared with the other samples due to the relatively good wear resistance and friction properties of NCD films.