Estimation of temperature in the cutting area during orthogonal turning of grade 2 titanium

Abstract

AbstractThe authors introduce an experimental-analytical method for determining the average temperature values in the PSZ (primary shear zone) and the SSZ (secondary shear zone) during orthogonal turning of grade 2 titanium with a use of an uncoated carbide tool with a positive rake angle and a flat rake face. The presented method is based on an algorithm in which the values of shear stress in the PSZ and the SSZ are calculated by means of the Johnson–Cook constitutive equation and Oxley’s model of cutting mechanics. Average temperature values in the PSZ and the SSZ are determined by iteratively finding the minimum difference between the calculated stress values. As its inputs, the algorithm uses the values of the feed and the tangential cutting force components, the value of chip flow velocity on the rake face, and the constants of the Johnson–Cook constitutive equation. The model was validated with a use of empirical data collected during the experiments. The test rig consisted of a KNUTH Masterturn 400 precision lathe equipped with a dynamometer, a high-speed camera, and a thermal imaging camera.