Investigating amorphization as a deformation mechanism using a novel phase field model at the mesoscale

Amorphization during severe plastic deformation has been observed in various crystalline materials, yet its underlying mechanisms remain poorly understood. This study introduces a novel phase-field model at the mesoscale, integrating elastoplastic theory with a deviatoric stress-dependent transformation strain tensor to capture stress-induced amorphization. The model enables quantitative predictions of amorphous phase nucleation and propagation under high stress, resolving distinctive micro-structural patterns such as amorphous shear bands. Simulations reveal key phenomena, including avalanche-like amorphization, grain size effects, the Hall–Petch effect, and surface amorphization, consistent with experimental observations. By bridging phase-field methods with elastoplastic theory, this work provides a robust framework for studying amorphization as a deformation mechanism and offers valuable insights for designing materials resistant to extreme mechanical conditions.