Papers by Author: Gui Wen Kang

Abstract: With the rapid development of modern optics and correlative science and technology, hard-brittle materials such as optical glass, optical crystal and glass ceramic have very important applications in the fields of military, space and aviation, electronics and so on. It is of great importance to research optical machining method for hard-brittle materials for the development of science and technology. Different kinds of ultra precision machining methods have been developed to meet different industry requirement. Such as chemical mechanical polishing, precession polishing and magnetorheological finishing, etc. Under most conditions the optical surface after ultra precision machining would have certain contaminant particles and this would affect its working ability in future use. Formerly the polished workpiece is cleaned by flowing water or ultrasonic cleaning and the contaminant particles couldn’t be totally removed. Laser cleaning is brought forward in this paper and good results could be anticipated.

Abstract: With the development of photoelectron technology, optical glass and glass ceramic has been used in many different fields. The final machining of this kind of material has very important effect to its future application. In the present study, optical glass and glass ceramic is finished using laser polishing. Laser polishing could eliminate subsurface damage, smooth micro roughness. In certain cases a preheating system should be needed to increase optical glass’ surface integrity. The result shows that laser polishing of optical glass and glass ceramic has higher efficiency compared to conventional optical machining. The flexibility of laser polishing makes it ideal as an enabling technology for the final manufacturing of optical glass and glass ceramic.

Abstract: Magnetorheological finishing (MRF) is a novel precision optical machining technology. Owing to its flexible finishing process, MRF can eliminate subsurface damage, smooth rms micro roughness and correct surface figure errors. Through proper designing of numerical control, sphere and asphere optics can be machined by magnetorheological finishing with high quality. Owing to it’s excellence in optical manufacturing, MRF has gained more and more application in industry. Under most conditions the optical surface after MRF would have certain contaminant particles and this would affect its working ability in future use. Formerly the polished workpiece is cleaned by flowing water or ultrasonic cleaning and the contaminat particles couldn’t be totally removed. Laser cleaning is brought forward in this paper and good results could be anticipated.

Abstract: Magnetorheological finishing (MRF) is a novel precision optical machining technology. Owing to its flexible finishing process, MRF can eliminate subsurface damage, smooth rms micro roughness and correct surface figure errors. The finishing process can be easily controlled by a computer. Through proper designing of numerical control, sphere and asphere optics can be machined by magnetorheological finishing with high quality. Optical sphere is machined using dwell time algorithm and surface shape 2 pt. PV has been improved from 0.17um to 0.07um.

Abstract: Three dimension indenter model was established to replace the ideal shape indenter model in the study of nano-indentation simulation. The limitation of short of comparing to actual condition can be solved. Single crystal aluminum surface nano-indentation on the condition of arc indenter is researched by molecular dynamic simulation. The influences of different arc radius of indenter head to testing results are discussed and compared to experiment results. The results show that The measured hardness value increases with indenter head arc radius on the same indentation depth condition. With the increase of indentation depth, the difference between measured results with changed indenter head arc radius reduces gradually. When the indentation depth increase to a certain value, the arc effect of indenter head could be ignored, the measurement will be invariable.

Abstract: Magnetorheological finishing (MRF) is a novel precision optical machining technology. Owing to its flexible finishing process, MRF can eliminate subsurface damage, smooth rms micro roughness and correct surface figure errors. The finishing process can be easily controlled by a computer. Material removal model in MRF is established. According to Preston equation in optical machining, mathematic model of material removal rate in MRF rotating at fixed rate is established through hydrodynamic analysis of the MR fluid flow in the polishing zone. The validity of the model is examined by the experimental results.

Abstract: Magnetorheological finishing (MRF) is a novel precision optical machining technology. MRF utilizes magnetic particles, nonmagnetic polishing abrasives in carrier fluid, and a magnetic field to finish optical materials. Owing to its flexible finishing process, MRF eliminates subsurface damage, corrects surface figure errors and the finishing process can be easily controlled by computer. To achieve deterministic finishing, it’s necessary to know the mechanism of material removal. Different magnetorheological fluids are used to finish optical glass on the same machining condition. The material removal and surface quality are examined after finishing with no polishing abrasive, aluminium oxide and cerium oxide. The results show that the hardness of polishing abrasive is not the main factors to affect material removal.

Abstract: In the process of ultra-precision grinding, workpiece can be ground with the arc area of the superfine and super hard arc-forming wheel. It is of great significance to study the precision dressing technology for super hard arc-forming wheels. EDM (Electron Discharge Machining) dressing can be the ideal dressing method for metal-bond super hard arc-forming wheel. Dressing device with pendulant electrode was designed. Polarity effects and the influences of different electrical parameters on wheel dressing efficiency and accuracy were studied in the experiments. The forming results showed that EDM dressing can satisfy the dressing requirement of arc-forming wheel.

Abstract: ELID grinding is widely used as a high-productivity and super-precision grinding method for hard and brittle materials. It continues grinding stably with metal bonded diamond wheel due to its in-process dressing. Magnetorheological finishing (MRF) is a novel precision finishing process for hard and brittle materials. In this paper, ELID grinding and MRF are adopted to get high surface quality and remove subsurface damage of hard and brittle materials. The results show that this combination gives attention to both efficiency and quality and can be used to replace conventional optics manufacturing.