Mechanism-Oriented Analysis of Core–Shell Structured CIP@SiO2 Magnetic Abrasives for Precision-Enhanced Magnetorheological Polishing

This study addresses the critical challenge of precise control over active abrasive particles in magnetorheological polishing (MRP) through innovative core-shell particle engineering. A sol-gel synthesized CIP@SiO₂ magnetic composite abrasive with controlled SiO₂ encapsulation (20 nm shell thickness) was developed using tetraethyl orthosilicate (TEOS) as the silicon precursor, demonstrating significant advantages in optical-grade fused silica finishing. Systematic polishing experiments reveal that the core-shell architecture achieves a remarkable 20.16% improvement in surface quality (Ra = 1.03 nm) compared to conventional CIP/SiO₂ mixed abrasives, with notably reduced surface defects despite a modest 8-12% decrease in material removal rate. Through synergistic analysis combining elastic microcontact mechanics modeling and molecular dynamics simulations, we establish that the SiO₂ shell mediates stress distribution at tool-workpiece interfaces, effectively suppressing deep subsurface damage while maintaining nano-scale material removal efficiency. The time-dependent performance analysis further demonstrates that extended polishing durations with CIP@SiO₂ composites progressively eliminate mid-spatial frequency errors without introducing new surface artifacts. These findings provide fundamental insights into designed abrasive architectures for precision finishing applications requiring sub-nanometer surface integrity control.