Effect of laser surface texturing on Si3N4/TiC ceramic sliding against steel under dry friction

Abstract

In efforts to investigate the influence of the surface texturing on the Si3N4/TiC ceramic, laser surface texturing (LST) was performed on the Si3N4/TiC ceramic by an Nd:YAG laser and different geometrical characteristics of regular-arranged micro-grooved textures were fabricated on the surfaces. The tribological properties of the textured and smooth samples were investigated by carrying out sliding wear tests against steel balls under dry condition using a ball-on-disk tribometer. Effect of surface texturing on the stress distribution was studied by finite element method (FEM). Results show that the textured surfaces exhibited lower friction coefficient and excellent anti-wear properties compared with smooth surfaces. The tribological characteristics depended greatly on the size and density of the micro-grooves, and the geometrical characteristics of the surface textures have a significant effect on the tribological behavior. Among the patterns investigated, the wavy-grooved samples exhibit the lowest friction coefficient and wear rate; and a large texture density may be the best for reduction of friction and wear of textured samples. While, the wear rate of balls sliding against textured surfaces is larger than that of balls sliding against smooth surfaces. FEM results show that surface texturing can improve the stress distribution of contact interfaces and reduce stress concentration.