The tribo-corrosion behavior of amorphous carbon (a-C) films under the extreme hydrostatic pressures and hypersaline electrolyte conditions of deep-sea environments was systematically investigated using a multi-scale framework integrating ReaxFF reactive molecular dynamics and density functional theory (DFT)-based first-principles calculations. Static corrosion simulations in hypersaline electrolyte confirm that ReaxFF-based molecular dynamics reliably captures corrosion induction phenomena within nanosecond timescales, validating the simulation framework. Dynamic tribo-corrosion simulations of self-mated a-C/a-C tribopairs across a coupling of NaCl concentrations and contact pressures reveal that the friction coefficient is governed predominantly by contact pressure rather than electrolyte salinity. A novel grid-based DFT sampling strategy, designed to explicitly account for the coordination heterogeneity of the disordered a-C surface, reveals that Cl⁻ adsorption is strongly site-dependent and inversely correlated with local coordination, whereas H2O adsorption is primarily physisorptive. Moreover, these two electrolyte species exhibit distinct temporal signatures at the tribological interface. Cl⁻ ions undergo rapid, load-induced preemptive chemisorption prior to sliding, while mechanochemically activated H2O dissociation progressively grafts –OH and –H groups onto the a-C surface throughout the sliding process. The collective action of Cl⁻ chemisorption, dissociative water passivation, and transient cross-interface C–C constitutes a multi-component tribochemical mechanism that underpins the exceptional tribological stability of a-C films in harsh marine environments.

amorphous carbon films, tribo-corrosion, reactive molecular dynamics, competitive interfacial passivation