One of the great challenges in solid mechanics is to prevent the degradation in strength of components. In particular, at high temperatures material may deform even at low stresses, a deformation mode known as deformation creep. It is well established that this deformation is governed by dislocation motion due to absorption or emission of vacancies, which results in motion perpendicular to the glide plane, called dislocation climb. However, the importance of the dislocation network on the deformation creep is still far from being understood. It is assumed by most climb models in literature that the dislocation network is homogeneous and dilute, which allow treating each dislocation as isolated. However, this is not always the case, such as in dislocation dipoles, dislocation pile ups, dislocation walls etc.
In this work we develop a climb model that accounts for the collective effect of the dislocation network. The climb rate of edge dislocations, in the presence of a dislocation network, is calculated analytically, and is implemented on several dislocation structures. The model reproduces previous models for isolated dislocations, but allows treating dense dislocation structures. We show here that if two neighboring dislocations are close to each other, one dislocation may climb on the expense of the other. This model is important to understand how metals deform in creep conditions with more realistic dislocation structures. In particular, this coordinated climb motion of neighboring dislocations is important to the disassembly of dislocation pile-ups. Finally, we discuss the importance of our results to modeling deformation creep.
