Assessment of Steady-State Metal Cutting Temperature Models Based on Simultaneous Infrared and Thermocouple Data

Abstract

Several models for metal cutting temperatures which could be applied in simulation programs have been reported in the literature. Since the temperature predicted by the models are difficult to measure, however, there is not sufficient experimental data to determine which available model is most accurate and whether further theoretical refinement is needed. In this paper calculations from four steady-state cutting temperature models are compared with simultaneous infrared and tool-chip thermocouple temperature measurements from end turning tests on 1018 steel, 2024 aluminum, free machining brass, and gray cast iron tubes. Deformation zone temperatures calculated using the models are compared to source temperatures determined from infrared measurements using a new inverse method. Calculated tool-chip contact temperatures are compared to rake face temperatures measured by the widely used tool-work thermocouple method. The data indicates most models, though quantitatively accurate, overestimate cutting temperatures. Models based on Jaeger’s friction slider solution which include workpiece thermal property variations, however, generally give results accurate to within the reliability of experimentai methods for the materials tested. Loewen and Shaw’s model, recently generalized to three-dimensional cutting by Venuvinod and Lau, seems most accurate over a broad range of workpiece and cutting conditions. No model accurately predicts tool-chip temperatures for cast iron or 2024 aluminum, indicating that further theoretical refinement for discontinuous chip formation is needed.