Synergistic Effect of MoS(2) and SiO(2) Nanoparticles as Lubricant Additives for Magnesium Alloy–Steel Contacts

The tribological performances of the SiO(2)/MoS(2) hybrids as lubricant additives were explored by a reciprocating ball-on-flat tribometer for AZ31 magnesium alloy/AISI 52100 bearing steel pairs. The results demonstrated that the introduction of SiO(2)/MoS(2) hybrids into the base oil exhibited a significant reduction in the friction coefficient and wear volume as well as an increase in load bearing capacity, which was better than the testing results of the SiO(2) or MoS(2) nanolubricants. Specifically, the addition of 0.1 wt % nano-SiO(2) mixed with 1.0 wt % nano-MoS(2) into the base oil reduced the friction coefficient by 21.8% and the wear volume by 8.6% compared to the 1.0 wt % MoS(2) nanolubricants. The excellent lubrication behaviors of the SiO(2)/MoS(2) hybrid nanolubricants can be explained by the micro-cooperation of different nanoparticles with disparate morphology and lubrication mechanisms.