Simultaneous laser in-situ generation of graphene and micro-textures on ductile iron and their effects on tribological properties

In this study, a picosecond (ps) laser was employed to produce micro-textures on ductile iron in linearly processing leading to significantly higher processing efficiency. The fabri-cation efficiency was increased about 1331 times as compared to the more common spot-by-spot texturing method. The ps laser induced graphene (LIG) structures were simulta-neously fabricated in dimples, which further enhanced the surface tribological properties. The surface micro-textures were produced by forming micro-dimples on the substrate via the laser ablation process. The dimple diameter and area density were regulated by varying the key laser processing parameters, and were experimentally correlated to the tribological properties of the ductile iron substrate. To understand deeper into the wear reduction mechanism of the micro-dimples, simulation models based on the Reynold equation were established, which analyze the flow field pressure distribution and demonstrate the hy-drodynamic lubrication effect of the micro-textures. The ball-on disk friction test showed that the area density of the micro-textures had a significant influence on the friction and wear properties. The micro-texture with the area density of 20% and the average dimple diameter of 36 mm showed the highest volume wear rate reduction of 70% and the friction coefficient reduction of 20% respectively. The results indicated that the simultaneous laser in-situ generation of graphene micro-textures is an effective way of enhancing tribological properties on the ductile iron surface. It enhances the hardness of textured surfaces, thermal diffusion, debris capture ability, and fluid dynamic lubrication effect. (c) 2021 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

This study utilized a picosecond laser to create micro-textures on ductile iron, enhancing processing efficiency and tribological properties. By correlating laser processing parameters with tribological properties of ductile iron, the research established simulation models based on the Reynold equation to understand the wear reduction mechanism of micro-dimples. The results showed that the generation of graphene micro-textures through laser processing effectively enhanced the tribological properties of the ductile iron surface.