The aim of this paper is to propose an analytical model of chip formation for precise prediction of orthogonal cutting of Ti6Al4V. This alloy is used broadly in aerospace components; hence, prediction of thermomechanical parameters of its orthogonal cutting is crucial for various industrial applications. The suggested analytical model needs only cutting parameters and tool geometry as input; it can predict not only cutting forces but also main features of a primary shear zone and a tool-chip interface. A non-equidistant shear zone model is employed to calculate shear strains and a shear strain rate in the primary shear zone, and a simplified heat-transfer equation is used for temperature. A Calamaz-modified Johnson-Cook material model that accounting for flow softening at high strains and temperature-dependent flow softening is applied to assess shear stresses in the primary shear zone. In addition, a shear-angle solution is modified for Ti6Al4V. At the tool-chip interface, a contact length, equivalent strain and an average temperature rise are defined. Besides, the effect of sliding and apparent friction coefficients is investigated. For a sawtooth chip produced in the cutting process of Ti6Al4V, the segmentedchip formation is analysed. A chip-segmentation frequency and other parameters of the sawtooth chip are also obtained. The predicted results are compared with experimental data with the cutting forces, tool-chip contact length, shear angle and chip-segmentation frequency calculated with the developed analytical model showing a good agreement with the experiments. Thus, this analytical model can elucidate the mechanism of the orthogonal cutting process of Ti6Al4V including predictive capability of continuous and segmented chip formation.

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This paper aims to reveal the material removal mechanisms of the elliptical vibration cutting (EVC) and present the predicted model of orthogonal cutting force. Further study of mechanism will be helpful to explain the phenomena that EVC can reduce the cutting force, lower cutting temperature, and improve the surface integrity. In each overlapping EVC cycle, almost all the parameters are time-varying, of which two important factors are focused: (i) transient thickness of cut and (ii) transient shear angle. The analysis model simplified the complex process of the EVC as conventional cutting (CC) which considering two transient variables. This paper presents a non-equidistant shear zone model to predict the shear angle, tool-chip friction angle, and shear stress in CC under the same conditions of the EVC. Then, the transient thickness of cut and transient shear angle are investigated. Thus, an analytical model of the force in EVC is proposed. The model is available to predict the cutting force of the EVC accurately without any experimental parameters in CC. In addition, experimental results available in the literature are conducted for comparison, which are in well agreement with the analysis model

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