Tribological Properties of SiO2@Cu And SiO2@MoS2 Core-Shell Microspheres As Lubricant Additives

Herein, core-shell structural SiO2@Cu and SiO2@MoS2 microspheres were prepared using SiO2 as hard core, Cu and MoS2 as shell. As lubricant additives were introduced into base oil (PAO 40), their friction-reduction and wear-resistance were investigated in detail. Comparing with onefold additive (SiO2, Cu and MoS2), such core-shell structure additives can improve the tribological behaviors at the Hertz contact stress range of 1.26 ~ 2.72 GPa (SiO2@Cu reduces the friction and wear up to 32.47% and 67.86% at 2.72 GPa, respectively). Besides, the tribological properties of SiO2@Cu microspheres are superior to that of SiO2@MoS2 (the wear volume was reduced by 48.45% at 2.72 GPa). The excellent tribological behaviors of SiO2@Cu microspheres can be ascribed to its structural advantage, the synergistic effect of hard SiO2 core and Cu shell. The rolling effect of SiO2, easy-shearing and self-repairing of Cu shell offer a synergistic lubrication function and form a dense protection film, thereby contributing to the optimal lubrication performance.