Multiphysics investigation of thermo-mechanical behavior and mechanisms in small-hole tapping of Ti6Al4V alloy

Abstract. This study employs a thermo-mechanical coupled simulation to investigate the tapping process, analyzing the mechanical behavior, thermodynamic characteristics, and variations in the tap pressure field during thread formation. The simulation results reveal that tapping constitutes a progressive material removal process accompanied by severe plastic deformation and friction. The three-dimensional cutting force curves indicate that the axial force follows a three-stage variation pattern, whereas the radial force exhibits periodic alternating loads, reflecting the dynamic nature of multi-edge cutting. Furthermore, contact pressure fields and torque curves demonstrate that friction between the tap and the machined surface accounts for a substantial portion of the overall torque. Temperature field analysis further identifies localized high-temperature zones at the cutting edges. Through multiphysics simulation, this research elucidates the stress and temperature distributions within the tap, providing a theoretical foundation for optimizing tap geometry, selecting suitable process parameters to reduce cutting loads, control machining temperatures, and enhance tool life and thread quality.