Multiphase dynamic interfaces and abrasive transport dynamics for abrasive flow machining in shear thickening transition states

Shear thickening polishing (STP) is a sophisticated machining technique employed in the surface polishing of chip wafers. The shear thickening effect governs the behavior of abrasive particles in STP, making it crucial for achieving desired outcomes. Microbubbles significantly impact the multi-phase interfacial evolution and grinding particle erosion mechanisms in the shear thickening process. Hence, this study investigates the multiphase shear thickening polishing process in the presence of bubbles. It introduces a variable viscosity profile for three-stage shear thickening fluids and proposes a three-phase shear thickening coupling calculation method based on CFD-DEM. The model's reliability is verified through bubble rise experiments, enhancing the accuracy of multi-phase interface morphology prediction. The research elucidates the four phases of microbubble interfacial evolution and reveals their influence on shear thickening. Moreover, it uncovers the kinematic features of abrasive particles affected by microbubbles and highlights the non-uniform characteristics of their impact on grinding efficiency.