SKM 2021 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 1: Topical Session Interface-Dominated Phenomena - Moving Interfaces

MM 1.3: Vortrag

Montag, 27. September 2021, 10:45–11:00, H8

Dislocation path and long-range strain associated with interface migration — •Jin-yu Zhang, Zhi-peng Sun, Fu-zhi Dai, and Wen-zheng Zhang — School of Materials Science and Engineering, Tsinghua University, Beijing

Major interphase interfaces generated from phase transformations in steels or Ti alloys are semicoherent. The knowledge of dislocation motion and long-range strain accompanying the interface migration is fundamental to the understanding of phase transformations. In this study, we performed a molecular dynamics simulation on the migration of various α/β interfaces in pure Ti. The simulation results explicitly demonstrated that the interfacial dislocation path can deviate significantly from the slip planes of individual dislocations due to the dislocation interaction when the interface contains multiple sets of dislocations. For these complex situations, previous theories based on conventional slip planes would lead to either non-atom-conservation or slip-sequence-dependent results. We developed a new geometric model, which is capable to generate self-consistent descriptions on the dislocation path and the shear displacement during migration of a general semicoherent interface, in the condition that atoms are conserved during interface migration. This model is validated by the simulations and it covers the simple cases applicable by previous theories. The present study offers new insight into the dislocation path during interface migration and provides a general framework for evaluating the long-range strain caused by interface migration during a phase transformation process, such as precipitation and martensite transformation.