M. H. Sein, Manchester Metropolitan University, Manchester, United Kingdom; W. Ahmed, University of Ulster, Newtownabbey, United Kingdom; M. J. Jackson, Purdue University, West Lafayette, IN; R. Polini, Universita’ di Roma “Tor Vergata”, Rome, Italy, Rome, Italy

Summary: In this paper we report results of our investigation on the CVD of both nanocrystalline and polycrystalline diamond films onto WC-Co dental burs. Bias enhanced nucleation has been investigated and used to reduce the crystal sizes and produce smooth nanocrystalline diamond films. The growth rate, surface morphology, crystallinity, adhesion and surface roughness of both nano and polycrystalline diamond have been compared. The adhesion of the coating working surfaces of the tool and the performance and life are compared. It is evident that CVD diamond coated burs display a better performance than uncoated WC-Co burs. In addition, surprisingly the polycrystalline diamond, which has micro cutting edge, gives better performance than nanocrystalline diamond films in terms of surface finished on machining materials.