High adhesion and quality diamond films on steel substrate

A process to deposit a diamond coating on steel substrates has been successfully developed. It includes the electroplating of nickel by using an electrolyte dispersed with micro-diamonds, and then a diamond deposition through a microwave plasma chemical vapor deposition system. The diamond films were characterized by Raman and CL spectroscopy, XRD, SEM and SEM line scanning. The results show a high diamond crystal quality, low residual stress (about 0.67 GPa) and high nucleation density. The adhesion of the films was evaluated by a cutting test and an interface examination. The results show that the retentivity of the diamond grits in the films after the cutting test is much better than that in the commercial electroformed diamond tools. The advantages of the process are: (1) the formation of nickel-carbon-hydrogen alloys to enhance diamond nucleation and growth, (2) the micro-diamonds acting as the seeds for diamond nucleation and growth, and forming effective mechanical interlocking with the nickel interlayer, and (3) the formation of good diffusion bonding of the nickel interlayer with the steel substrate. (C) 1998 Elsevier Science S.A.