A hybrid dislocation

ABSTRACT

The shear of a crystalline interface by a matrix dislocation is an elementary phenomenon of plasticity that generates a three-dimensional elastic field difficult to express. However, in the case of a flat interface and two elastic isotropic media, the present work shows that this field can be described starting from an explicit form of the Green tensor associated with a point force exerted in one of the crystals. Indeed, the knowledge of this tensor makes it possible to express the displacement field of a dislocation in the final form of a surface integral. Because the shear is limited by a matrix branch and an interfacial branch, the dislocation can be called ‘hybrid dislocation’ or HD. If the two branches are straight, the field is that of an angular HD. Moreover, if the crystals are identical, the field becomes that of an angular matrix dislocation whose field is well known since Yoffe (1960). By applying the superimposition theorem, it becomes possible to determine the field of more complex configurations, such as those sometimes observed during the transmission of the plastic slip through the interfaces.

KEYWORDS:

• Dislocation interactions
• interfaces
• elasticity
• crystal defects

Acknowledgement

One of the authors (Dr Salem Neily) wishes to thank the University of Monastir (Monastir, Tunisia) for financial support of the work.

Disclosure statement

No potential conflict of interest was reported by the author(s).