Properties of dislocation drag from phonon wind at ambient conditions

Abstract

It is well known that under plastic deformation, dislocations are not only created but also move through the crystal, and their mobility is impeded by their interaction with the crystal structure. At high stress and temperature, this `drag' is dominated by phonon wind, i.e. phonons scattering off dislocations. Employing the semi-isotropic approach discussed in detail in Ref. [arXiv:1804.01586], we discuss here the approximate functional dependence of dislocation drag $B$ on dislocation velocity in various regimes between a few percent of transverse sound speed $c_t$ and $c_t$ (where $c_t$ is the effective average transverse sound speed of the polycrystal). In doing so, we find an effective functional form for dislocation drag $B(v)$ for different slip systems and dislocation characters at fixed (room) temperature and low pressure.

arXiv comment10 pages, 5 figures, 6 tables; v2: minor revision; v3: fixed typos, tables recomputed with PyDislocDyn 1.2.5 (more accurate)

References in corpus (8)

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• Dynamic Peierls-Nabarro equations for elastically isotropic crystals
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Cited by in corpus (6)

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• Dislocation drag from phonon wind in an isotropic crystal at large velocities
• Dislocation drag and its influence on elastic precursor decay
• Limiting velocities and transonic dislocations in Mg
• On the temperature and density dependence of dislocation drag from phonon wind
• A general solution for accelerating screw dislocations in arbitrary slip systems with reflection symmetry