Experimental study on the effect of bionic lunate surface textures on the dry friction performance of Cr4Mo4V steel

To enhance the dry friction performance of bearing steel Cr4Mo4V, bionic lunate micro-textures, inspired by the low-adhesion lunate structures found on the pitcher plant's peristome, were designed and fabricated on its surface. The tribological behaviors of these textures with varying area densities under dry sliding conditions were investigated, with a focus on analyzing the influence of texture anisotropy. Results indicate that the lunate textures can reduce the coefficient of friction under specific conditions, with the effectiveness being co-influenced by area density and sliding direction. The optimal friction-reducing effect was observed at an area density of 6%, with reductions in the average friction coefficient of 0.95% and 3.16% in the horizontal and vertical directions, respectively. Microscopic analysis revealed that the primary mechanism behind friction reduction is the ability of the textures to capture and store wear debris, thereby mitigating abrasive wear. This study provides experimental evidence supporting the application of bionic textures for friction reduction design on bearing component surfaces.