Tribological characteristics of dimpled surfaces filled with dopamine-modified MoS2

To improve the tribological characteristics of dimples on the surface of 45 steel, the dimples were filled with MoS₂ and MoS₂ modified by dopamine (MoS₂ @ DA), and ball-disk friction and wear tests were conducted. Specifically, the dimple filling gap, abrasion depth, and surface cross-sectional area of 45 steel were measured. The wear morphology of the friction ball and exfoliation of MoS₂ in the dimples and the bending characteristics of the specimens were studied. The surface friction coefficient of MoS₂ @ DA-filled specimen was 17.9% lower than MoS₂-filled specimen, and the dimple filling gap was 70.1% lower, the surface abrasion depth was 5.8% lower, and the abrasion cross-sectional area was 17.7% smaller. Moreover, the bending strength of the MoS₂ @ DA specimen was 3.27 times greater than that of the MoS₂ specimen, and the exfoliation of MoS₂ was slowed by filling with the MoS₂ @ DA. Finally, the tribological characteristics were also superior for the specimens prepared with MoS₂ @ DA.