Determination of optimum numerical parameters in a 3D model of finish turning operation applied to Inconel 718

Abstract Finish turning operation consists in a three-dimensional cutting process carried out to accurate size removing a very thin chip section from the work-piece. In this paper, we propose a numerical model of finish turning operation applied to Inconel® 718. The work is focused on the determination of optimum numerical parameters (mesh size and deletion element criterion) for the modeling of chip removing process: 1/ at least 10 elements in the feed direction are needed to predict the cutting forces with accuracy; 2/ the calibration of shear element deletion is a fundamental key: its value affects drastically the temperature distribution in the machined piece. A numerical study on global variables (cutting forces and chip morphology) and local variables (strain, strain rates and temperature) in the chip is presented and discussed. Finally a comparison with experimental measurements in term of forces shows a good accuracy with numerical predictions (the average relative error between numerical and experimental forces is around 2% considering a cutting speed Vc = 300 m/min).