Abstract

In deterministic microgrinding of glass optics with metal bonded diamond ring tools, optical surfaces exhibit residual cutting tool marks that can significantly affect the efficiency of the finish polishing process. The tool marks for spherical surface generation appear as curves that follow contact lines between the tool and workpiece from the center to the edge of the workpiece. The tool marks are circumferentially periodic and the number is typically equal to the k-ratio, i.e. the ratio of grinding tool speed to workpiece speed. This paper describes the effect of k-ratio, tool bevel size, tool vibration, tool roughness and their interaction on tool mark generation. We introduce a new parameter equal to the ratio of tool bevel size to the distance between two adjacent tool marks. Preliminary experimental results indicate that this ratio is the critical factor for tool mark generation. For ratios greater than a critical value, the amplitude of tool marks will be reduced to a level not detectable by interferometry. An analytic model is introduced, which describes the relations between surface quality and grinding parameters including part geometry, tool bevel size, tool speed, work speed, tool vibration amplitude and tool roughness. The model presented provides new insight into the generation of tool marks and optimization of deterministic microgrinding processes.

© 1998 Optical Society of America