▎ 摘　　要

This research reports the antifriction and antiwear properties of Mn3O4-Graphene nanocomposites (Mn3O4-G) as additives of a paraffinic base oil commonly used in the formulation of electric vehicles transmission oils, G-III base oil. Four G-III base oil nanodispersions have been designed, G-III base oil + 0.025 wt% Mn3O4-G, G-III base oil + 0.050 wt% Mn3O4-G, G-III base oil + 0.075 wt% Mn3O4-G and G-III base oil + 0.100 wt% Mn3O4-G, to know the optimal concentration of nanoadditive. Tribological experiments were carried out with these nanolubricants and with neat G-III base oil at pure sliding con-ditions under a working load of 9.43 N. All tested nanolubricants led to similar friction coefficients in comparison to that obtained using G-III base oil. Tribological specimens tested with formulated nanolu-bricants revealed less wear than that obtained with G-III base oil, obtaining the greatest wear reduction using the G-III base oil + 0.075 wt% Mn3O4-G nanolubricant, with reductions of 25, 50 and 64% in wear scar diameter, maximum depth and transversal area, respectively. Moreover, by means of confocal Raman microscopy and roughness evaluation of worn tribological specimens, it was concluded that syn-ergetic effect, tribofilm formation and rolling mechanisms happen.(c) 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http:// creativecommons.org/licenses/by/4.0/).