Development of a novel Ductile-machining system for fabricating axisymmetric aspheric surfaces on brittle materials

A ductile machining system based on the straight-line enveloping method is developed for fabricating convex axisymmetric aspheric surfaces on hard brittle materials. This system enables thinning of undeformed chip thickness in the nanometric range by using a straight-nosed diamond tool on an X-Z-B 3-axis ultraprecision machine tool, capable for simultaneous numerical control. The configuration of the system and the cutting tests for a large-scale single-crystal silicon aspheric lens are described. The results indicate that the developed system improves production efficiency and tool life significantly, compared to the conventional method.