적외선 우주망원경용 렌즈의 제작기술 개발

Machining technique for optical crystals with single point diamond turning tool is reported in this paper. The main factors influencing the machined surface quality are discovered and regularities of machining process are drawn. Optical crystals have found more and more important applications in the field of modem optics. Ge is more brittle material of poor machinability. The traditional machining method is polishing which has many shortcomings such as low production efficiency, poor ability to be automatically controlled and edge effect of the workpiece. The purpose of our research is to find the optimum machining conditions for ductile cutting of Ge and apply the SPDT technique to the manufacturing of ultra precision optical components of Ge. As a result, the surface roughness is good when cutting speed is 180m/min, feed rate is 2㎜/min, depth of cut is 0.5㎛ and nose radius of tool is 0.8㎜.