Magnetic Liquid Metal Assisted Abrasive Impact Regulation and Local Material Removal Mechanism for Surface Integrity Enhancement of Ti–6Al–4V Alloy

During abrasive flow polishing of complex curved surfaces, weak-flow regions such as concave and curvature transition areas suffer from insufficient near-wall abrasive transport and reduced particle impact, resulting in heterogeneous material removal and degraded surface integrity. This study proposes a magnetic liquid metal particle-mediated abrasive flow polishing strategy to regulate particle–material interactions and improve the surface integrity of Ti–6Al–4V alloy components. The near-wall abrasive impact behavior, coupled collision dynamics between magnetic liquid metal particles and SiC abrasives, and local material removal mechanism were established and investigated through explicit dynamic simulations and polishing experiments. The results reveal that abrasive radius, initial velocity, and incident angle jointly influence the localized stress response of Ti–6Al–4V surfaces. An abrasive radius of 7.5 μm, initial velocity of 5 m/s, and incident angle of 60° achieved a balanced stress concentration and affected region. Coupled collision analysis demonstrates that impact enhancement is not monotonically dependent on particle diameter or velocity. A magnetic liquid metal particle diameter of 200 μm and velocity of 3 m/s produced the highest instantaneous equivalent stress through effective momentum transfer and localized energy concentration. Experiments confirmed that magnetic-field-assisted polishing promotes near-wall particle enrichment and improves surface uniformity. After 12 h polishing, the regional roughness difference ΔSa decreased from 114.15 nm to 30.69 nm, representing a 73.11% reduction. These findings provide insights into magnetic-field-controlled particle impact regulation and surface integrity modification of advanced titanium alloys.