IWP-based Flexible Polishing Tools for Improving Hydrodynamic Fluid Polishing Performance of BK7 Glass
Polishing of BK7 optical glass suffers from rapid tool wear, low material removal rates, and unstable surface quality. This study introduces an internal-configuration optimization strategy for flexible polishing tools based on I-graph-wrapped package (IWP) triply periodic minimal surface unit cells. Two complementary architectures—skeletal lattice (IWP-1) and perforated lattice (IWP-2)—were fabricated via stereolithography (SLA) photocuring additive manufacturing at Shore A hardness levels of 35 A and 60 A. A corrected material removal function was developed by coupling Hertzian contact theory, the Preston equation, and effective abrasive count, with elastic-plastic deformation analysis of individual grains. Static finite element analysis revealed that IWP topologies homogenize contact pressure and reduce stress concentration. CFD-DPM/DEM fluid-structure interaction simulations showed that internal channels and surface depressions enhance slurry supply, circulation, and abrasive spatial distribution. Orthogonal polishing experiments (three factors, three levels) identified optimal parameters: IWP-1 at 2 mm compression and 60 A hardness achieved Ra = 0.033 μm, suitable for final polishing; IWP-2 at 2 mm compression and 35 A hardness achieved Ra = 0.075 μm with a material removal rate ηMRR = 0.0558 mm³/min, suitable for pre-polishing. These results demonstrate a tunable balance between removal efficiency and surface quality, providing a structural design framework for non-Newtonian hydrodynamic polishing of hard-brittle optical components.