Edge dislocation impingement on interfaces between dissimilar metals

Robbert-Jan Dikken (1) , Mohsen Khajeh Salehani (1)

1 TU Delft - Delft University of Technology

In this work, the effect of material dissimilarity on the impingement behavior of a dislocation on the interface of a bi-crystal is investigated. To this end, impingement of a single edge dislocation on a Ni-Al interface is studied using molecular dynamics simulations. A dislocation is inserted in either aluminum or nickel and forced to impinge on the interface by an applied compressive load on the bi-crystal. We observe that the contact contains defects due to the lattice mismatch between the materials and hence, the dislocation may impinge on an interface defect or between two defects. Our results show that the dislocation is directly absorbed by the contact only if it impinges on an interface defect. Furthermore, it is demonstrated that dislocation transmission occurs only when it is initially in the Ni crystal. This is explained by looking at the energy of the core of a dislocation. Moreover, the importance of atomic vibrations is emphasized by performing the simulations at two temperatures 100 mK and 10 K.

Mots clés: molecular dynamics; dislocation impingement; interfaces; defects; aluminum; nickel

Domaines: Science des matériaux [cond-mat.mtrl-sci]; Mécanique des matériaux [physics.class-ph]; Matériaux et structures en mécanique [physics.class-ph]; Mécanique des solides [physics.class-ph]

Robbert-Jan Dikken, Mohsen Khajeh Salehani. Edge dislocation impingement on interfaces between dissimilar metals. 2017. ⟨hal-01572509⟩