Influence of Boriding Process in Adhesion of CVD Diamond Films on Tungsten Carbide Substrates

Abstract

AbstractThis paper shows successful hindering of the negative effects of the cobalt binder in the process of coating WC-Co cutting tools with CVD diamond films. The strategy was creating a boron-rich layer on the surface of the WC-Co substrates as an interlayer to block Co migration. The traditional boriding technique was improved by preheating the salt powders and controlling the brittle region thickness in the substrate surface. These procedures produce a tougher surface for diamond growth. Adding CF4 to the gas mixture also enhanced diamond adhesion to the surface. The adhesion of diamond films to WC-Co substrates was evaluated by indentation tests. Samples were characterized by Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDX), X-ray Diffraction (XRD) and Raman Scattering Spectroscopy (RSS).

Keywords

• boriding
• HFCVD
• diamond film
• diffusion