Force decomposition model for tool-wear in turning with grooved cutting tools

The lack of a satisfactory methodology to predict the tool-wear progression/tool-life in a machining operation with a grooved tool necessitates development of quantitative predictive models for tool-wear. This paper presents a new methodology for decomposing and distributing the resultant force generated in machining with a grooved tool within the three major tool-wear regions: edge region, secondary-face region, and groove backwall region. By measuring the edge force from the experiments, the forces acting on the other two major wear regions can be found from the kinematics of the 3-D chip-flow and the geometry of the tool insert. The Coulomb coefficient of friction is assumed only at the groove backwall region. The effect of chip side-flow is considered by measuring the chip side-flow angle from experiments using high speed filming techniques. With the new methodology, the decomposed forces acting on the wear regions can be related to the dominant wear modes of a grooved tool. The new methodology implicitly includes the influencing parameters on tool-wear, including cutting conditions, tool geometry and chip-groove geometry, since changes in these parameters are reflected in the cutting forces. This force decomposition method offers a new approach for predicting the cutting tool-wear analytically using the measured cutting forces.