Machining performance and mechanism of surface-active-media-assisted milling for 18Ni300

18Ni300 maraging steel is difficult to machine, commonly exhibiting high cutting forces, degraded surface integrity, and accelerated tool wear. To address these issues, this study investigate surface-active media (SAM) assisted milling using DYKEM High Purity 44 marker ink to activate the Rehbinder effect, in which polar molecules adsorb on the workpiece surface, reduce surface energy, and promote near-surface dislocation motion and microcrack initiation, thereby lowering local fracture toughness. Comparative milling experiments were conducted, and a corresponding ABAQUS/Explicit FEM model was developed by representing the R-effect via reduced fracture energy. Experimentally, SAM reduced average cutting forces by ~25%, while improving surface integrity (suppressed tearing and reduced roughness) and decreasing tool wear under identical conditions. FEM results corroborate the trend, predicting a 39.59% reduction in specific cutting force with SAM.