Journal of Materials Research and Technology (May 2022)
Tribological properties of laser surface texturing modified GCr15 steel under graphene/5CB lubrication
Abstract
Dimple-textured surfaces of square arrays with different geometrical parameters (area density, diameter and depth) were prepared on the surface of GCr15 steel. The friction and wear experiments were carried out under the lubrication of Suspension of graphene and liquid crystal 4-n-pentyl-4'-cyano biphenyl (5CB). By controlling the area density, diameter and depth of the dimples, the lubrication performance of laser surface texturing under the condition of starved lubrication was analyzed, and the reducing friction and wear resistance mechanism of laser surface texture was preliminarily discussed. The lubrication performance of the dimple-textured surface is best when the depth of the dimple is 10 μm, the area density is 8%, and the diameter is 100 μm. The friction coefficient at this textured parameter is 0.031, which is a 32.6% decrease compared to the untextured surface (0.046). The reduction friction mechanism of the textured surface is mainly to improve load-bearing capacity, store lubricant, reduce contact area and secondary lubrication. Meanwhile, XPS analysis shows that during the friction, the graphene/5CB suspension has a tribochemical reaction in the textured surface, and a chemical reaction film is formed on the steel surface. The research results can provide theoretical guidance for the optimization of texture geometric parameters under different application conditions.
