Avalanches and Scaling in Plastic Deformation

摘要: Plastic deformation of crystalline materials is a complex non-homogeneous process characterized by avalanches in the motion dislocations. We study evolution dislocations loops using an analytically solvable phase-field model for ductile single crystals during monotonic loading. present simulations under slow external loading that generate scale-free and power-law behavior are characteristics self organized criticality. The distribution dislocation loop sizes given P(A) {approx} A{sup -{sigma}}, with {sigma} = 1.8 {+-} 0.1. power law exponent agreement those found acoustic emission measurements on stressed ice crystals. In addition to jerky character motion, this also predicts range macroscopic behaviors observation, including hardening multiplication maximum signal at onset yielding. At sufficient large stress, rate drops stress-strain curve saturates. same time as well production decreases experimental observation.