Tribological Performance of Short Carbon Fiber Reinforced Polyphthalazine Ether Ketone Composites: Experimental and Molecular Dynamics Insights

Polymer composites show great application potential in the field of tribology, yet existing studies mainly focus on dry friction conditions with limited exploration of microscopic mechanisms at the atomic scale. This study systematically evaluates the tribological properties and underlying micro-mechanisms of short carbon fibers (SCF)-reinforced polyphthalazine ether ketone (PPEK) composites under different lubrication conditions. Experimental results demonstrate that the addition of 15 wt% SCF reduces the friction coefficient and wear rate of PPEK by 42.25% and 94.79% respectively under dry friction. Tribological performance is significantly influenced by lubrication conditions, with optimal performance observed under oil lubrication. A three-layer Fe-polymer-Fe friction pair model was constructed for molecular dynamics (MD) simulations, revealing that SCF decreases atomic concentration at the friction interface by 4.56%, reduces interface temperature by 45 K, and lowers interfacial interaction energy by 20.59%, thereby inhibiting adhesive wear. This work provides critical references for expanding the application of SCF/PPEK composites in marine and aerospace fields by elucidating the micro-mechanisms of SCF-reinforced tribological enhancement at the atomic scale.