Researchers at Osaka Metropolitan University and the Fraunhofer Institute for Mechanics of Materials IWM have challenged conventional engineering assumptions by demonstrating that chemical impurities enhance lubricity in carbon-based materials. Their findings, published in Advanced Science, reveal that oxygen and similar elements stabilize nano-voids in amorphous carbon, facilitating the reorganization of adjacent carbon atoms into aromatic, graphene-like configurations that exhibit superlubricity. This counters the traditional view that material purity correlates directly with performance quality. The research addresses fundamental challenges in tribology by explaining why shear-induced aromatization occurs at sliding interfaces under certain conditions but not others.
The study focused on the tribological properties of carbon allotropes, which exhibit vastly different frictional characteristics depending on their atomic arrangements. Graphite's layered structure enables near-frictionless sliding, while diamond's rigid three-dimensional lattice resists deformation. Amorphous carbon, lacking long-range order, can transform into graphitic phases at contact points, though maintaining such structures in practical applications has remained problematic. Through quantum-mechanical molecular dynamics simulations, the team identified impurity-driven mechanisms that promote and sustain low-friction interfaces. These results suggest potential applications for self-regenerating protective coatings in mechanical systems where sustained润滑 performance is critical.