An improved method to model dislocation self-climb

Journal article

Dislocations can provide short circuit diffusion paths for atoms resulting in a dislocation climb motion referred to as self-climb. A variational principle is presented for the analysis of problems in which fast dislocation core diffusion is the dominant mechanism for material redistribution. The linear element based self-climb model, developed in our previous work [1] Liu, Cocks and Tarleton (2020 J. Mech. Phys. Solids 135 103783), is significantly accelerated here, by employing a new finite element discretisation method. The speed-up in computation enables us to use the self-climb model as an effective numerical technique to simulate emergent dislocation behaviour involving both self-climb and glide. The formation of prismatic loops from the break-up of different types of edge dislocation dipoles are investigated based on this new method. We demonstrate that edge dipoles sequentially pinch-off prismatic loops, rather than spontaneously breaking-up into a string of loops, to rapidly decrease the total dislocation energy.

Authors: Liu, F; Cocks, ACF; Gill, SPA; Tarleton, E

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: IOP Publishing
• Journal: Modelling and Simulation in Materials Science and Engineering More from this journal
• Volume: 28
• Issue: 5
• Article number: 055012
• Publication date: 2020-06-04
• Acceptance date: 2020-03-20
• DOI: 10.1088/1361-651x/ab81a8
• EISSN: 1361-651X
• ISSN: 0965-0393
• Language: English
• Keywords: pipe diffusion; core diffusion; variational principle; FFR; self-climb