Particle size effects on polishing quality and abrasive flow mechanism in quartz glass

Abrasive flow polishing media consist of micrometer-sized rigid abrasives dispersed in a viscoelastic polymer matrix. In this work, we investigate how abrasive particle size and the particle size-gap ratio (D/H) govern rheological behavior and polishing performance for quartz glass. Steady shear and normal-stress measurements (0.1–100 s−1) show that the first normal stress difference N1 increases as particle size decreases; at 100 s−1, N1 rises from 4672.9 (D: 28 μm) to 17 098 Pa (D: 1.5 μm). To link rheology with material removal, it couples a particle-size-dependent viscosity model with a White–Metzner viscoelastic formulation and introduces an N1-based correction to the effective normal load in the removal function. The model identifies two distinct flow regimes governed by D/H: a free-flow regime (D/H < 0.046) and a strongly confined regime (D/H > 0.058), in which jamming/quasi-rigid behavior alters the stress field. In the free-flow regime, the predicted removal agrees with experiments within ∼9.3% error. Based on the combined requirements of low roughness and adequate removal rate, an optimal parameter window of approximately D ∼ 5 um with H ∼ 150 um is recommended, yielding Ra ∼ 3–6 nm on quartz glass surfaces.