Investigation of form control and surface integrity during belt polishing polycrystalline magnesium aluminate spinel (PMAS) ceramics with large grain

Abstract

Belt polishing (BP) is emerging as an up-and-coming technique for polishing thin-walled deep-cavity (TW-DC) optical elements. Developing a polishing process that can determinately remove material to ensure high surface integrity is crucial for enhancing the performance and life of optical elements. Developing a polishing process capable of deterministically removing material to ensure high surface integrity is crucial for enhancing the performance and service life of optical components. This study investigated the surface integrity control strategies and the polished surface quality of large-grain PMAS ceramics associated with belt polishing. Firstly, a flat deterministic material removal (DMR) model based on path planning was established for the BP process. The precise flat DMR path was generated for the BP process combined with in-situ measurement. Secondly, four uniform material removal (UMR) path planning methods were proposed for the BP process. These methods were compared and analyzed through simulation, thereby verifying the superiority of the spiral path planning for the polishing process of rotationally symmetric components. The effectiveness of the UMR path planning was validated through flat polishing experiments using various polishing parameters, followed by an integrity evaluation of the polished surface. Finally, a UMR-BP process experiment on a wafer workpiece manufactured of spinel with large grains was carried out utilizing the optimized polishing process parameters, and the form error of the wafer workpiece was reduced from 60 μm to 1 μm. The results substantiate the validity of the developed DMR model for the BP process, and it can provide valuable guidance for achieving high quality during the polishing of TW-DC optical components.