Phonon scattering during dislocation motion inducing stress-drop in cubic metals

摘要: Abstract This work proves that scattering of elastic waves in the dislocation core induces an unusual behavior called stress-drop , which is defined for first time this study as a phenomenon where externally applied stress drops inside nano-sized cubic metal during motion. We develop theoretical phonon model based on discrete lattice dynamics and derive simple analytical equations to quantify magnitude stress-drop. The proposed supported by atomistic simulations perfect dislocations bcc iron, resulting from bond breaking inversely proportional square speed. derived equation excellent agreement with direct edge screw dislocations. Next, we extend fcc aluminum exists stacking fault ribbon surrounded two Shockley partial thus interaction between them important. extended accurately predicts scattering, oscillation partials well breaking. In addition discussion validity our at absolute zero, investigate temperature size effects equations. As increases, decreases converges zero even very low because extremely small Peierls barrier. Moreover, decreases, thickness nanoplate shows mechanical prominent nanoscale.