Modeling Cutting Temperatures for Turning Inserts With Various Tool Geometries and Materials

Abstract

Temperatures are of interest in machining because cutting tools often fail by thermal softening or temperature-activated wear. Many models for cutting temperatures have been developed, but these models consider only simple tool geometries such as a rectangular slab with a sharp corner. They do not simultaneously account for tool nose radii and insert shape effects, even though it is known in practice that these features affect tool life and thus presumably tool temperature. This report describes a finite element study of tool temperatures in cutting that accounts for tool nose radius and included angle effects. A temperature correction factor model that can be used in the design and selection of inserts is developed to account for these effects. Parametric mesh generator is used to generate the finite element models of tool and inserts of varying geometries. The steady-state temperature response is calculated using NASTRAN solver. Several finite element analysis (FEA) runs are performed to quantify the effects of insert’s included angle, nose radius, and materials for the insert and the tool holder on the cutting temperature at the insert rake face. The FEA results are then utilized to develop a temperature correction factor model that accounts for these effects. The temperature correction factor model is integrated with an analytical temperature model for rectangular inserts to predict cutting temperatures for contour turning with inserts of various shapes and nose radii. Finally, experimental measurements of cutting temperature using tool-work thermocouple technique are performed and compared with the predictions of the new temperature model. The comparisons show good agreement.