Dislocation Multiplication and Cyclic Slip Localization in HfNbTa Under Reconstructed Strain Fields Associated with Chemical Short-Range Order

Chemical short-range order (CSRO) is associated with heterogeneous lattice distortion in refractory multi-principal-element alloys, but its relationship with cyclic dislocation organization remains unresolved. Hybrid Monte Carlo and molecular dynamics simulations were combined with statistical field reconstruction and three-dimensional discrete dislocation dynamics to examine cyclic deformation in HfNbTa. Structure–function analysis of the atomistic strain fields provided the descriptors used to reconstruct heterogeneous strain fields for the as-cast and annealed samples. These reconstructed fields served as the direct inputs to the DDD simulations. Under the simulated loading conditions, the as-cast sample exhibited wider hysteresis loops and approximately four times the final dislocation density of the annealed sample. In the examined network realization, the annealed sample developed a lower-density network with a narrower diagonal concentration of dislocations. Projected band width characterized the transverse extent of this feature. Additional comparisons showed comparable macroscopic stress responses across the tested initial dislocation arrangements and field phases. These results distinguish dislocation storage from spatial organization under the two sample-specific CSRO-associated reconstructed fields; the diagonal morphology is an observation within the examined realizations.