Comparison of Johnson–Cook and TANH Plastic Models for 3D Numerical Modeling of Turning Titanium Alloy Ti5553

The near-beta titanium alloy Ti5333 with high strength is difficult to cut, and accurate FE simulation models are needed to assess its machinability. This work compares for the practical turning process of the performances of two material plastic models, i.e., the Johnson–Cook model without strain softening and the TANH model with strain softening. To obtain accurate simulation results, the parameters of the JC model are directly determined from the quasi-static/dynamic compression test results, whereas the non-physical meaning parameters of the TANH model are obtained from the machining tests using an inverse method. The comparison results reveal that the TANH model predicts the cutting forces with smaller simulation errors in both the cutting speed and feed directions and gives larger force amplitude variations closer to the experimental variations. In addition, the simulation results from the TANH model generate smaller residual stresses and plastic strains than the JC model as the TANH model gives smaller flow stresses and lower temperatures due to the strain softening effect. The verified FE simulation models can be further used for cutting process optimization of near-beta alloy Ti5333.