Dislocation stress-field and solute-strengthening predictions based on minimal ab-initio input

D Fioravanti and JPMH Institute and E van der Giessen and F Maresca, COMPUTATIONAL MATERIALS SCIENCE, 258, 113991 (2025).

DOI: 10.1016/j.commatsci.2025.113991

Solid solution strengthening is a powerful strategy for enhancing the yield strength of materials through alloying. Recent theories have effectively predicted solute-strengthening effects, but their application relies on the accurate characterization of the dislocation core and the solute/dislocation interaction energy map. In this study, starting from minimal DFT input we employ the Peierls-Nabarro model in combination with Stroh's dislocation theory to model the dislocation core and stress field, and subsequently derive interaction energy maps. The interaction energy maps are then used to predict the critical resolved shear stress in alloys. This approach is tested on materials with different crystal structures (HCP and FCC), for dislocations with both narrow and wide cores, and for crystals with isotropic and anisotropic elastic properties. Our results are carefully validated against molecular statics simulations, to analyze the robustness and accuracy of the method, and to highlight its limitations and possible directions of improvement. We identify best modeling practices and apply them to predict solute strengthening effects ab initio, comparing our predictions with experimental data. The approach produces good results for Mg-Zn and Zn-Cu alloys, showing reasonable agreement with experimental strengthening trends and capturing the key physical mechanisms. These findings demonstrate that ab initio predictions of solute strengthening are achievable with satisfactory accuracy while maintaining minimal computational cost, providing an efficient framework for future studies.

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