Research progress of shear-thickening polishing technology: A review

Shear-thickening polishing (STP) is an emerging precision polishing technology that dynamically adjusts the viscosity of polishing fluid by precisely controlling the shear rate, thereby enhancing material removal rate (MRR) and surface accuracy while effectively suppressing surface defects such as scratches and microcracks commonly found in conventional polishing methods. This expands its potential applications in high-tech fields such as precision manufacturing and microelectronics. Studies have shown that under optimized parameters (polishing speed: 70 rpm, polishing angle: 70°, abrasive particle concentration: 12 wt%), STP achieves an MRR of up to 813.63 nm/min on optical glass. Additionally, under conditions of 38 °C, abrasive particle size of 0.6 μm, polishing speed of 600 rpm, and abrasive particle concentration of 12 vol%, adaptive shear-gradient thickening polishing (AS-GTP) can reduce the subsurface damage depth and surface roughness (Ra) of lithium niobate (LN) crystals to below 1 nm. However, research on STP remains fragmented, and a comprehensive review is currently lacking. To bridge this gap, this article systematically reviews the primary types of shear-thickening polishing fluid based on the shear-thickening characteristics of non-Newtonian fluids and provides an in-depth discussion of the working mechanisms and process optimization strategies of different STP methods. Finally, the latest advancements in STP are summarized, and its future development trends and industrialization challenges are analyzed.