关键词: 弹性作用, 刃型扩展位错, 孔洞, 夹杂相, 相场模型

Abstract: The dynamics of the extended dislocation passing through the void and inclusion in the face-centered cubic (FCC) crystals of aluminum (Al) and copper (Cu) under shear stress were simulated by phase-field method combined with the phase-field microelasticity (PFM) theory and the Peierls-Nabarro (PN) model, respectively. The PFM theory was employed to calculate the long-range elastic interaction between the dislocation and the void (or the inclusion phase), the PN model was used to describe the structure of the extended dislocation based on the one-dimensional crystal energy function, and the Ginzburg-Landau dynamic equation was used to describe the movement of the dislocation. The simulated results showed that when the dislocation slips to the void, the dislocation is attracted to the edge of the void first and then pinned and finally depinned. When the dislocation slips to the inclusion phase, the dislocation is first bent by the inclusion and then passes through the inclusion with a dislocation loop left. Moreover, in the case that the stacking fault (SF) energy is relatively low, it was found that the SF narrows when the extended dislocation approaches the void (or the inclusion phase). While an extended dislocation passes through the void (or the inclusion phase), the leading partial dislocation passes through the void first, and then the trailing partial dislocation passes through the void, which is also accompanied by the phenomenon of SF broadening. Our simulation results are not only consistent with the previous atomic simulated results, but also further reveal the effects of stress amplitude and SF energy parameters on the dynamics of the extended dislocation passing through the void (or the inclusion) at a longer time scale.

Key words: elastic interaction, edge extended dislocation, void, inclusion, phase field model