A novel magnetic assistant polishing technology

摘要

The fabrication of the aspheric optics is quite important in optical engineering. In this paper, a novel magnetic assistant polishing technology and device is researched to complete the finish step of the optics. As the device working, the magnetic powder arranged with the magnetic field distribution. The magnetic powder became a brush. The magnet wheel working with a high rolling velocity and the polishing liquid with abrasive is injected to contact region. The magnetic powder brush is reforming with the magnetic field all the time, so the removal tool of the fabrication is invariable. The device, as shown in Fig. 1, is connected to the CNC machine and experiment is completed to get the removal function. As shown in Fig. 2, the shape of the removal function is like a raindrop and asymmetry in one orientation. The shape is different with tradition CCOS removal function, which is circular symmetry. The removal stability of the device is also researched. The experiment work-piece is K9 glass plane, and the effectual abrasive is CeO2. the total fabrication time is about one hour. This four spot is fabricated in sequence, the interval time is 15 minutes. The surface error is measure by Zygo interferometer, and the data is deal with MetroPro software. The peak value of the removal function is 0. 526X,0. 528X,0. 552X.O. 549X. The maximal removal difference is 2. 5%. Therefore, as shown in Fig. 3, the removal stability of magnetic assistant polishing device is 97. 5 % in one hour. The roughness of the final surface achieved Ra 1. 4 nm. The research make quite good precondition to fabricate high precision aspheric optics.