*Article* **Interdependent Linear Complexion Structure and Dislocation Mechanics in Fe-Ni**

**Vladyslav Turlo 1,2 and Timothy J. Rupert 2,3,\***


Received: 13 November 2020; Accepted: 8 December 2020; Published: 11 December 2020

**Abstract:** Using large-scale atomistic simulations, dislocation mechanics in the presence of linear complexions are investigated in an Fe-Ni alloy, where the complexions appear as nanoparticle arrays along edge dislocation lines. When mechanical shear stress is applied to drive dislocation motion, a strong pinning effect is observed where the defects are restricted by their own linear complexion structures. This pinning effect becomes weaker after the first dislocation break-away event, leading to a stress-strain curve with a profound initial yield point, similar to the static strain aging behavior observed experimentally for Fe-Mn alloys with the same type of linear complexions. The existence of such a response can be explained by local diffusion-less and lattice distortive transformations corresponding to L10-to-B2 phase transitions within the linear complexion nanoparticles. As such, an interdependence between a linear complexion structure and dislocation mechanics is found.

**Keywords:** linear complexions; dislocations; strength; lattice distortive transformations
