Acoustic emission during plastic deformation of crystals: A lattice-dynamics approach

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Abstract
A lattice-dynamics approach to acoustic emission during plastic deformation of crystals is proposed. First the dynamics of a dislocation interacting with transverse acoustic waves is investigated on the basis of a microscopic Frenkel–Kontorova model in which the rigidity of the substrate is relaxed. It is shown that the interaction can be described by a d’Alembert wave equation for the elastic displacement coupled to a sine-Gordon equation that governs the dislocation dynamics. Within the framework of this model and considering the soliton nature of dislocations, two basic mechanisms of acoustic emission are investigated both analytically and numerically: One is the accelerated motion of dislocations and the other is the annihilation of dislocation kink-antikink pairs during Frank–Read source operation. The results are discussed on the basis of existing experimental data.