Effect of surface integrity on quality factor of hemispherical resonator

Abstract

Since hemispherical resonator (HSR) is core component of hemispherical resonator gyro (HRG), the surface integrity directly determines performance parameters of HSR, which then affects the working accuracy and service life of HRG. Therefore, it is necessary to investigate the effect of surface integrity on quality factor of HSR. This work focuses on the surface integrity evolution of fused silica HSR machined by the multi-energy field coupled magnetorheological polishing (MEMRP) and the influence of surface integrity on quality factor. Firstly, the mechanism of removing subsurface damage and surface morphology evolution of the fused silica component machined by MEMRP were investigated to reveal the surface quality evolution rules. It was found that the removal of subsurface damage in fused silica components can be divided into three zones: rapid improvement zone, slow improvement zone, and gentle improvement zone. The improvement of surface roughness is slow in the gentle improvement zone, and the nonlinear regression model between subsurface damage depth and surface roughness is proposed. Then, the surface structure evolution and the mechanical characteristics of the surface layer of fused silica components during the MEMRP process was systematically analyzed. It was found that the initial polishing stage significantly improved the surface mechanical performance parameters. Finally, the quality factor of HSR with various surface qualities was measured. The results show that the subsurface damage depth and quality factor exhibit nonlinear relationship and the crack surface layer has a significant impact on the quality factor. Completely removing the subsurface damage, quality factor of HSR with diameter of 20 mm increased from hundreds of thousands to 2.01×10⁷, and the uniformity of quality factor is 1.2 %. This work could offer theoretical guidance and parameter basis for quickly removing subsurface damage and achieving high-performance manufacturing of fused silica HSR.