Study on the preparation and fretting behavior of bonded oriented MoS2 solid lubricant coating

Abstract

The bonded MoS2 solid lubricant coating is an effective measure to mitigate the fretting wear of AISI 1045 steel. In this work, the amino functionalized MoS2 was protonated with acetic acid to make the MoS2 positively charged. The directional arrangement of protonated MoS2 in the coating was achieved by electrophoretic deposition under the electric field force. The bonded directionally aligned MoS2 solid lubricant coating showed high adaptability to various loads and excellent lubrication performance under all three working conditions. At a load of 10 N, the friction coefficient and wear volume of the coating with 5 wt% protonated MoS2 decreased by 20.0% and 37.2% compared to the pure epoxy coating, respectively, and by 0.07% and 16.8% than the randomly arranged MoS2 sample, respectively. The remarkable lubricating properties of MoS2 with directional alignment were attributed to its effective load-bearing and mechanical support, barrier effect on longitudinal extension of cracks, and the formation of a continuous and uniform transfer film.