Analyzing and modelling the accelerated stress relaxation caused by pulsed current of Ti₂AlNb alloy foils

Analyzing the electrically-assisted stress relaxation behavior of Ti₂AlNb alloy is beneficial for improving the forming accuracy of Ti₂AlNb alloy thin-walled components. This study analyzes and models the deformation mechanism of Ti₂AlNb alloy foils during the electrically-assisted stress relaxation process. The non-thermal effect of pulsed current on the stress relaxation of Ti₂AlNb alloy foils was decoupled using forced air cooling. As the current density increases, it promotes dislocation recovery and O-phase precipitation, significantly accelerating the stress decrease in stress-driven stage I of the stress relaxation process. However, extensive precipitation of the O phase hinders dislocation movement, reducing the stress relaxation rate in stage II. A physically-based constitutive model was developed, considering the effects of pulsed current on activation energy, dislocation evolution, and phase transformation, with a relative average absolute error of 8.7%.