Abstract
This paper deals with the step generated at the grain boundary in an ultra-precision diamond cutting of phosphor bronze for a typical metal mold of Fresnel lens. In this study, the cutting experiments were carried out with an ultra-precision cutting machine by a single crystal diamond tool in order to investigate the relationship between the generation of grain boundary step and the cutting conditions. The influence of the thrust force component and the heat treatment on the step at grain boundary is discussed. It was found that the thrust component of the cutting force and the feed rate condition greatly influence the magnitude of the step at grain boundary.
