Low-Temperature-Graphitized and Interpenetrating Network C/Fe₃O₄ Magnetic Nanocomposites with Enhanced Tribological...

Although the core-shell structure magnetic nanocomposites have been widely used as lubricant additives, their tribological properties are still poor under high temperature and high load. Herein, the graphitized C/Fe₃O₄ magnetic nanocomposites (g-C/Fe₃O₄) with an interpenetrating network structure were successfully fabricated by an in situ hydrothermal carbonization method combined with a subsequent ball milling process at room temperature. The results showed that the ball milling process not only promoted the transformation of graphitized carbon but also effectively eliminated the interfacial effect between carbon and Fe₃O₄. Moreover, the g-C/Fe₃O₄ used as a lubricant additive in rapeseed oil exhibited excellent tribological properties and high thermo-stability under 155 °C and 980 N, with the friction coefficient reduced by 32.8% compared to the independent Fe₃O₄. The enhanced tribological performance of g-C/Fe₃O₄ could be attributed to the graphitized carbon and its interpenetrating network structure under low load force (392 N), while under high load force (980 N), it could be ascribed to the synergistic effect between the graphitized carbon and magnetic Fe₃O₄ nanoparticles. This work not only offers a method for the synthesis of nanocomposite lubricant additives but also shows great potential in practical applications for high-temperature tribology.