Atomic irradiation defects induced hardening model in irradiated tungsten based on molecular dynamics and CPFEM.

• Interaction mechanisms between dislocations and irradiation-induced defects revealed. • Atomically-informed evolution formula for dislocations and defects established. • Creation of crystal plasticity model (CPFEM) incorporating MD-derived formula. • Successful simulation of nano-indentation, tension, and compression processes. • Practical implications for predicting irradiated tungsten behavior. Tungsten plays a significant role in the nuclear industry, in which defects are generated upon exposure to irradiation. Irradiation-induced defects, such as dislocation loops and helium bubbles, are key factors in performance degradation, leading to irradiation hardening and embrittlement. The inner interaction between the dislocations and irradiation-induced defects directly determines the safety of the irradiated tungsten. However, the interaction mechanisms and evolutionary formulas remain unclear. In this study, based on systematic molecular dynamics (MD) simulations, an interaction mechanism phase map between the dislocation and dislocation loop was built as a function of the dislocation loop size and temperature. An atomically-informed mechanism-based evolution formula for dislocations and dislocation loops due to their interaction was established. Subsequently, a crystal-plasticity finite-element model (CPFEM) that contains the evolution formula obtained by MD is proposed. Based on CPFEM, the nano-indentation, uniaxial tension, and compression processes were simulated. Good agreement was achieved between the simulated and experimental results, further demonstrating the reasonability of the proposed model. [ABSTRACT FROM AUTHOR]