Application of edge preparation technologies to improve tool performance

Abstract

In machining, tool life is the chief determinant of cost, tool changing frequency, machining efficiency, and machining precision. Application of a proper cutting edge with optimized geometry and suitable edge properties is an effective way to improve tool performance and machining quality. The majority of the reported work is limited to the effect of edge geometry on tool life. In this thesis, cutting edges were prepared using three different methods which were evaluated in terms of tool edge geometry produced, tool surface quality and topographies, edge hardness and residual stresses. Furthermore, the influence of cutting edge preparation techniques on the tool performance of uncoated tungsten carbide cutting inserts with different average cutting edge rounding (S¯), different form factor (K), as well as the different edge preparation methods used underwent experimental investigation through the orthogonal turning of AISI 4140 alloy steel. Results show that the performance of the prepared edge depends on the combined effect of micro-geometry and edge properties. For symmetric edges (K=1), the preferable range for S¯ was found to be 20 µm to 30 µm. Drag finishing was determined to be the best edge preparation process which is able to produce cutting edges with the best performance. The experimental investigations provided guidelines and evidence for future study of the cutting tool life and wear behavior of prepared cutting inserts and PVD-coated carbide inserts.