Research on dynamic constitutive model and broaching simulation of titanium alloy at low-speed cutting

Abstract

In the simulation of metal material cutting, an accurate constitutive model is indispensable, which can precisely simulate the behavior of workpiece material in the actual cutting circumstances. Nevertheless, the current research on broaching titanium alloy simulation is devoid of an accurate constitutive model applicable to low-speed cutting conditions. To address the void of the low-speed cutting constitutive model of TC11 titanium alloy, the dynamic mechanical properties of TC11 at medium and high strain rates (2000–6000 s⁻¹) and high temperature (25°C–400°C) were investigated by employing the separated Hopkinson pressure rod (SHPB). The Johnson-Cook (J-C) constitutive model was fitted and modified based on the strain hardening effect, strain rate strengthening effect, and thermal softening effect. The results demonstrate that the modified JC model can more accurately reflect the dynamic mechanical behavior of TC11 at 2000–6000 s⁻¹ and 25°C–400°C, and the average relative error is <10%. Based on this, characteristic parameters such as cutting stress and cutting temperature are obtained through finite element method (FEM), which can offer a reference for the selection and optimization of tool parameters.