Cutting Tool Edge Design for Longer Tool Life

Abstract

In metal cutting, the effects of edge preparation and tool wear are considered most critical, as they directly determine tool life, surface finish and properties of the subsurface layer. Proper selection and application of cutting tool edge preparation is one of the basic factors for a successfully manufactured and correctly performing cutting tool. In this regard, the use of cutting tools with honed and chamfered edges is ever increasing. This thesis develops a procedure to design a subtle feature on the cutting edge of an insert, which mimics as closely as possible the natural wear that occurs in the initial stage of wear and arrive at a geometry that is known to lead to stable wear. In this case the geometry that would naturally occur is established with minimal subsurface damage, thus leading to a longer tool life. Turning test data collected showed that using a 50(mu)m chamfer on the rake face of the insert could minimize tool flank wear. By applying a special coating on this newly created geometry, a significant increase in the stable stage of wear and an overall improvement in performance and productivity have been observed. The analysis of chip morphology showed an improved behavior in the case of chamfered coated inserts.