Molecular Dynamics Study on Characteristics of Misfit Dislocations in Ni-Based Superalloys

摘要

By using molecular dynamics simulation, misfit dislocation networks are made on semi-coherent interfaces in a laminate structure of Ni and Ni_3Al single crystals. The core structure of the networks is discussed in detail, focusing on the different atomic configuration at the interfaces; e.g. with or without Al atoms on the Ni_3Al side. It is revealed that the networks can be a source of partial dislocation loops under the external loading; however, the loops tend to form immobile wedge-like stacking faults, analogous to the stacking fault tetrahedron (SFT), near the interface with Al atoms. On the other hand, the loops propagate into both Ni and Ni_3Al phases, from the network dislocations on the interface without Al atoms.