우주망원경용 비구면 반사경 표면조도 향상을 위한 진화형 수치제어 연삭공정 모델

• Published in: Journal of astronomy and space sciences 2004, 21(2), , pp.141-152
• Main Authors: 한정열, 김석환, 김건희, 김대욱, 김주환, Jeong-Yeol Han, Sug-Whan Kim, Geon-Hee Kim, Dae-Wook Kim, Ju-Whan Kim
• Format: Article
• Language: Korean
• Subjects: 천문학
• ISSN: 2093-5587; 2093-1409

Optics fabrication process for precision space optical parts includes bound abrasive grinding, loose abrasive lapping and polishing. The traditional bound abrasive grinding with bronze bond cupped diamond wheel leaves the machine marks of about 20 $\mu$m rms in height and the subsurface damage of about 1 $\mu$m rms in height to be removed by subsequent loose abrasive lapping. We explored an efficient quantitative control of precision CNC grinding. The machining parameters such as grain size, work-piece rotation speed and feed rate were altered while grinding the work-piece surfaces of 20-100 mm in diameter. The input grinding variables and the resulting surface quality data were used to build grinding prediction models using empirical and multi-variable regression analysis. The effectiveness of such grinding prediction models was then examined by running a series of precision CNC grinding operation with a set of controlled input variables and predicted output surface quality indicators. The experiment achieved the predictability down to $\pm$20 nm in height and the surface roughness down to 36 nm in height. This study contributed to improvement of the process efficiency reaching directly the polishing and figuring process without the need for the loose abrasive lapping stage. KCI Citation Count: 0