Friction-reducing effect and damage mechanism of laser micro-texture on diamond films during friction

摘要

Diamond films are often applied in places where there is intense friction. The use of lasers to fabricate textured arrays on diamond films can effectively reduce the friction coefficient. In this paper, we use a UV nanosecond laser to produce periodic linear and pit micro-textures over the areas of 14 * 7 mm(2). Laser irradiation was below the single-pulse ablation threshold corresponding to the conditions of surface graphitization during the multi-pulse irradiation. Irradiated graphitization can be detected by Raman spectroscopy, and at the same time, lattice distortion and crack initiation that accompany graphitization can be obtained by XRD and SEM, respectively. The shape of the texture also has a great influence on the residual stress. Grooved texture released the residual stress, but pit texture gave rise to uneven stress, as shown in the test result. SEM was used for observing morphological change at the edge of texture and the mechanism of internal stress changes is analyzed. Detection of texture antifriction performance by reciprocating friction and wear tester. After rubbing, the layered shedding marks of the edge of the texture were observed, and the influence of the superposition of residual stress and external stress on the texture damage was proved based on this.