A molecular dynamics study on the tribological behavior of molybdenum disulfide with grain boundary defects during scratching processes

The effect of grain boundary (GB) defects on the tribological properties of MoS 2 has been investigated by molecular dynamics (MD) simulations. The GB defects-containing MoS 2 during scratching process shows a lower critical breaking load than that of indentation process, owing to the combined effect of pushing and interlocking actions between the tip and MoS 2 atoms. The wear resistance of MoS 2 with GB defects is relevant to the misorientation angle due to the accumulation of long Mo-S bonds around the GBs. Weakening the adhesion strength between the MoS 2 and substrate is an efficient way to improve the wear resistance of MoS 2 with low-angle GBs.