Laser processing parameter optimization and tribological characteristics of different surface treatment

Abstract

The laser surface processing parameters and tribological properties of a textured surface filled with Gr-MoS2-PI-carbon nanotube nanocomposite solid lubricant under oil lubrication were investigated. Micro-dimples were fabricated on GCr15-bearing steel material using Gaussian-shaped beam profile nanosecond semiconductor sound and light-pumped Nd:YAG laser machining equipment. Friction and wear tests were performed using MMW-1A testing machine with the flat-on-flat configuration under different conditions in air. The results show that micro-dimple morphology is affected strongly by the laser head to sample surface distance, pulse repetition frequency, and single pulse energy. Additionally, the textured surface filled with solid lubricant (TSL) exhibited an enhanced tribological performance as compared to the textured (T) and smooth (S) surfaces under dry friction condition. In the oil medium, the efficiency of the textured surface (TO) was 18%, while the textured surface filled with solid lubricant (TSO) was 22% as compared to the plateau smooth surface (SO). Furthermore, under different conditions of load and rotational speed, the solid-oil composite lubricating film effectively reduces the friction and wear on the surface of the sample. The research results identified that the good lubrication and anti-wear properties of the TSO sample were mainly attributed to the double-action lubrication system and synergistic lubricating effect generated by the composite solid lubricant and oil.