WEAR BEHAVIOR OF VARIOUS DIAMOND-COATED CUTTING TOOLS UNDER DIFFERENT DEPOSITION CONDITIONS

Abstract

A hot-filament-assisted chemical vapour deposition system was used to deposit diamond films on cemented carbide cutting tools with Co contents ranging from 6% to 22%. The surface roughness and friction coefficient of the films were measured under different deposition conditions. A block-on-ring tribotester and scanning electron microscopy were adopted to characterize the tribological behaviour and the film morphology. The results indicate that the cutting performance of the diamond-coated tools is closely related to the friction coefficient and surface roughness of the film and that the friction coefficient is a function of the surface roughness and film quality. For the 6% Co substrate the film deposited under 0.5% CH4 Concentration shows the best film quality and the lowest friction coefficient and its surface roughness is within the optimum range 0.06-0.25 mum; therefore it shows better cracking resistance and wear resistance.