High-efficiency chemical-thermal co-assisted small ball-end magnetorheological polishing of hemispherical resonators through optimization of chemical additives

This article unveils a cutting-edge chemical-thermal co-assisted polishing technique that addresses the long-standing challenge of efficiently fabricating hemispherical resonators—the core components of hemispherical resonator gyroscopes (HRGs) used in aerospace navigation systems. The research systematically explores how combining thermal assistance (60°C) with chemical additives can dramatically improve polishing efficiency and surface quality for fused silica hemispherical resonators, which are notoriously difficult to machine due to their fragile, thin-walled structure. The study begins by evaluating six different chemical additives—including sodium hydroxide, potassium hydroxide, and organic bases—revealing that sodium hydroxide delivers the optimal balance of high material removal rates (76% improvement) and ultra-smooth surfaces (surface roughness reduced to 6.8nm for a 30mm diameter resonator). The article then demonstrates how this method reduces total polishing time by up to 50% compared to traditional approaches, while maintaining critical performance parameters such as roundness errors below 0.19μm and quality factors exceeding 17 million. Notably, the research provides unprecedented insights into the mechanisms behind abrasive particle behavior in magnetorheological fluids, showing how chemical additives influence particle agglomeration, zeta potential, and fluid viscosity. The findings are validated through comprehensive experiments on both 20mm and 30mm diameter resonators, proving the method's scalability and reliability. Additionally, the article highlights the method's unique ability to simultaneously improve polishing efficiency and component performance—a rare achievement in precision manufacturing. For engineers and scientists working on high-precision gyroscopes, MEMS devices, or optical components, this research offers a transformative solution that bridges the gap between manufacturing efficiency and component performance, potentially accelerating the deployment of next-generation inertial navigation systems.