Evaluation of static cutting forces and tool wear in HSM process applied to pocket milling

Abstract

One of the main operations in the manufacturing of molds and dies is the opening of the initial pocket, from which more complex geometries are machined, in order to obtain the negative shape of the final product. Since this is a rough operation, high cutting forces and significant tool wear are observed. Aiming to reduce such parameters, several strategies of tool entry and internal cut of the pocket have been proposed. In this context, this work aims to evaluate the cutting forces in the different parts of a pocket milling, using three different strategies, which are composed by the tool, cutting conditions, tool entry, and tool trajectory (I: ramp entry with spiral internal cut, II: helical entry with zigzag internal cut, and III: plunge entry). The results obtained for strategies I and II showed an increase in the forces in the direction perpendicular to the face in which flank wear occurred and a sharp increase in force at points where the tool changes trajectory. In strategy III, the occurrence of tool fracture due to chip recut led to very high force values.