Prediction of cutting force and temperature rise in the end-milling operation

Abstract

The cutting force has a significant influence on the dimensional accuracy because of tool and workpiece deflection in milling. Force modelling in metal cutting is important for a multitude of purposes, including thermal analysis, tool life estimation, chatter prediction, and tool condition monitoring. In this paper, the dynamic cutting force model for end milling is developed to predict the tangential cutting force and the thrust force. The model prediction is validated with the experimental cutting forces during the machining of AISI 1020 steel using a three-axis milling tool dynamometer. The tool-chip interface temperatures for different machining conditions are determined using Oxley's energy partition function and Rapier's equation to study the thermal effect on the cutting force. Experiments have been conducted to validate the predicted temperature using a K-type thermocouple and an infrared pyrometer. The maximum temperature in the tool increased from 459 to 944 °C as the cutting speed is increased from 20 to 200 m/min when machining at a depth of cut of 2.5mm. The surface plots have been drawn using MATLAB to indicate the variation in the cutting temperature in shear and friction zone with the cutting parameters. Knowledge of the force acting on the cutter and tool-chip interface temperature may help the operator to select suitable cutting parameters in order to limit the tool-chip interface temperature.