Application of CVD nanocrystalline diamond films to cemented carbide drills

Nanocrystalline diamond coated cemented carbide drills were produced by high current extended DC arc plasma CVD system using Ar/H 2/CH 4 gas mixture. The deposited nanocrystalline diamond films were characterized with scanning electron microscopy. Raman spectroscopy was used to investigate the purity of the nanocrystalline diamond films. X-Ray diffraction was used to analyze the structure of the diamond films. The pretreatment with Murakami and acid solution could effectively remove the Co binder in the substrates and roughen the surface of the cemented carbide drills. A uniform and smooth surface morphology of nanocrystalline diamond thin film was observed. The cutting performance of the diamond coated drills was investigated by machining metal matrix composites. The deposition of nanocrystalline diamond thin films on cemented carbide drills is helpful to improve the cutting performance of the drills.