HKUST‐1 derived carbon nanocomposites as grease additives for friction and wear reduction

Abstract Lubricating greases are widely used in mechanical engineering, especially in rolling bearing. Carbon‐based materials show promise as lubricant additive for formulating high‐performance grease. However, the enhancement of lubrication performance of carbon‐based materials limits by the simple lubricating mechanism. This work demonstrates that nanocomposite of metal–organic frameworks (MOFs)‐derived carbon as a grease additive can improve the tribological properties of bentone grease. HKUST‐1 was synthesized by a solvent method and converted into HKUST‐1derived carbon (HDC) via one‐step pyrolysis sacrifice template method. After pyrolysis of HKUST‐1 at 350 °C, Cu 2+ was reduced to zero‐valence copper. With increasing pyrolysis temperature from 350 to 950 °C, both the particle size of copper in HDC and the degree of graphite defect increased gradually. Types of HDCs as base grease additives significantly improved friction‐reduction and anti‐wear performance of bentone grease. Compared with the base grease, HDC‐950 °C with the amount of 2 wt% addition reduced friction coefficient and wear volume loss by 35.5% and 97.0%, respectively. The superior tribological performance of the HDC‐950 °C is attributed to the synergistic effect of carbon and copper nanoparticles to induce tribochemical reaction, which form a stable protective film on the friction surfaces. This study highlights the potential of MOFs‐derived carbon for developing high‐performance grease additives.