MRF Researches On Discrete Planar Ultra-smooth Polishing Process

Ultra precision optical manufacturing technology is becoming a hot topics in the fields of science and engineering. The development of ultra precision manufacturing technology brings manufacturing technology into a new heights far beyond which traditional mechanical manufacturing technology can reach optical element performance parameters such as surface precision, roughness values, substract surface damage, surface residual stress etc are increasing demanded. High precision optical component producing is a very difficult process, which needs long time work, high level skills, large labor intensity, low production efficiency. Ultra smooth machining technology of optical crystal and glass ceramics, as the representative of the brittle optical materials, has become a hotspot of research.Magnetic rheological finishing technology (MRP) as a kind of intelligent deterministic processing technology, becomes more and more popular in the optical processing field for its advantages to ensure high surface quality, low subsurface damage and residual stress for optical materials processing. With several years of efforts, Xi’an Technological University has done many theory researches on contact type belt MRF technology and has invented the MRF engineering prototype, In order to verify the function and practical application of the band MRF engineering prototype, Xi’an Technological University optics manufacturing centre carried out a lot of experimental studies. it is necessary to discovery its effects to polish small optics plane element for a large polishing head diametered Φ300mm of the engineering prototype.This paper mainly discuss the polishing effects of belt MRF technology and discuss the surface roughness distribution of different place where small plane optics element was set on the sanding pad, three position distribution relationship included, radial distribution, angular distribution and element density distribution. Choosing K9glass sized15×15mm as the finishing optics element and sanding pad sized Φ200mm. the purpose of the experimental study’ s to get surface roughness value less than lnm and surface accuracy is lower than500nm.In the process of experiment, the edge defect phenomenon was found and its brought seriously quality damage definition of the edge defect phenomenon was that serious defect on the boundary of the optics element while the quality in the centre was very good. In the paper, analysis was given and new technology was designed to decrease the edge defect.Improvement measures to influence of edge effect have be taken according to the traditional polishing technology for low speed loop method, reducing the rotation speed of the grinding head and sanding pad and setting a correction plate, With the improved technology of correction of the MRF film, the surface shape of P-V improved from the original10λ reduced to0.6λ...