Stress effects on interaction modes and cross-slip annihilation distance of screw dislocation interactions

Phase field microelasticity model is used to study the cross-slip and annihilation of screw dislocations in face-centered cubic crystals, revealing the non-negligible effects of Escaig stress on dislocation interactions. We find that the Escaig stress (in the direction that expands the stacking fault width) promotes the partial dislocation interactions and the Fleischer cross-slip mechanism. In addition to three fundamental dislocation interaction modes, three new dislocation interaction modes emerge with the formation of parallel stacking fault bands. Furthermore, with the increasing of Escaig stress, the critical annihilation distance in dislocation interactions can be appropriately reduced. This research provides novel insights for manipulating strain hardening and understanding the formation of dislocation patterns.