Tribological Properties of Laser Microtextured Surface Bonded With Composite Solid Lubricant at High Temperature

Abstract

A combination technology of the solid lubricant and the laser surface texturing (LST) can significantly improve the tribological properties of friction pairs. The plate sample was textured by fiber laser and composite lubricant of polyimide (PI) and molybdenum disulfide (MoS 2 ) powders were filled in the microdimples. Sliding friction performances of micron-sized composite lubricant and nano-sized composite lubricant were investigated by ring-plate tribometer at temperatures ranging from room temperature (RT) to 400 C. On the one hand, the results of the micron-sized composite lubricant show that the friction coefficient of the textured surface filled with composite lubricant (TS) exhibits the lowest level and the highest stability compared to a textured surface without solid lubrication, smooth surface without lubrication, smooth surface burnished with a layer of composite solid lubricant. The better dimple density range is 35-46%. The friction coefficients of the sample surface filled with micron-composite solid lubricant with the texture density of 35% are maintained at a low level (about 0.1) at temperatures ranging from RT to 300 C. On the other hand, the results of the nano-sized composite lubricant show that these friction properties are better than those of MoS 2 -PI micron-sized composite. The friction coefficients of MoS 2 -PI-CNTs nano-sized composite solid lubricant are lower than those of the MoS 2 -PI composite lubricant at temperatures ranging from RT to 400 C. In addition, the possible mechanisms involving the synergetic effect of the surface texture and the solid lubricant are discussed in the present work.

Synergetic effects of surface texturing and solid lubricants to tailor friction and wear – A review

“…The most common layered material used in combination with texturing is MoS2. However, studies have been performed on WS2 [241,[245][246][247][248], WS2/Zr [245,249], Cr-WS2 [250], graphite/graphene/carbon-nanotubes (CNTs) [167,233,240,[251][252][253][254][255] , CaF2 [248,256], and hBN [248]. Images of textured surfaces coated with MoS2 and graphite are shown in Figure 15.…”

“…The inconsistencies in results from comparisons between graphitic materials and MoS2 are likely due to the environment sensitivity of these two materials, since MoS2 performs better in vacuum and graphite better in air. Moreover, studies have combined multiple solid lubricants, as done in studies of textures with MoS2/graphite/Sb2O3 [235], Mo/MoS2/Ag [163] and MoS2/CNTs [253]. Lastly, studies have evaluated the effect of the initial size of solid lubricant particles before application to texture and found that nanoscale MoS2 or graphite particles yield lower friction than the same material deposited in the form of microscale particles [253,255].…”

“…Moreover, studies have combined multiple solid lubricants, as done in studies of textures with MoS2/graphite/Sb2O3 [235], Mo/MoS2/Ag [163] and MoS2/CNTs [253]. Lastly, studies have evaluated the effect of the initial size of solid lubricant particles before application to texture and found that nanoscale MoS2 or graphite particles yield lower friction than the same material deposited in the form of microscale particles [253,255]. [233,236,238,248,258,265], Ti6Al4V [252,257,263,266], TiAlCN [163,267], WC/Co [239,242,243,251,261,268], Ni-Cr-W-Al-Ti-Ag alloy [269] and Al-Si alloy [264].…”

“…However, the magnitude of the coverage identified as best varied widely from study to study. Friction has been reported to either decrease with increasing density [237,265,266] or exhibit a non-monotonic relationship (decrease and then increase with increasing density) [233,253,257]. One study also reported that friction increased with increasing density [260].…”

Wetting Behavior and Tribological Properties of Polymer Brushes on Laser-Textured Surface

“…Laser surface texturing (LST) was recognized as an effective means of surface engineering to improve the tribological properties of sliding surfaces [14,15,16,17,18]. A combination of LST and solid lubricants was utilized to achieve friction reduction and extension on wear resistance life, as micro-dimples can reduce the contact area and protect lubricants in the pit from wear [19,20,21,22].…”