Tribological behaviour of diamond coatings sliding against steel: An experimental and numerical approach

The tribological properties of diamond coatings depend on their conditions of use, but are also greatly linked to the intrinsic characteristics of these films, more particularly to their adhesion to the substrate. This last point is treated in this work, through the study of the tribological behaviour of the diamond/HSS couple, from an experimental and numerical point of view. The influence of both the crystals orientation and the surrounding temperature on the conditions of decohesion is more particularly deepened: this work is focused on the determining of the critical load applied to the contact, which can induce the detachment of the diamond coating from its substrate.The results of the rubbing tests as well as the modelling indicate that the diamond-substrate cohesion is optimised when using {100} oriented diamond coatings rather than {111} ones, or when the friction occurs at 500 °C instead of at the ambient.