On the similarity of plastic flow processes during smooth and jerky flow: Statistical analysis

M.A. Lebyodkin (1) , N.P. P Kobelev (2) , Y. Bougherira (1) , Denis Entemeyer (1) , C. Fressengeas (1) , V.S. S Gornakov (2) , T.A. A Lebedkina (2) , I.V. V Shashkov (2, 1)

1 LEM3 - Laboratoire d'Etude des Microstructures et de Mécanique des Matériaux
2 ISSP - Osipyan Institute of Solid State Physics

Jerky flow in dilute alloys, or the Portevin-Le Chatelier effect, is investigated using statistical analysis of time series characterizing the evolution of the plastic activity at distinct scales of observation, namely, the macroscopic scale of stress serrations and a mesoscopic scale pertaining to the accompanying acoustic emission. Whereas the stress serrations display various types of statistical distributions depending on the driving strain rate, including power-law, peaked and bimodal histograms, it is found that acoustic emission is characterized by power-law statistics of event size in all experimental conditions. The latter reflect intermittency and self-organization of plastic activity at a mesoscopic scale. This shift in the observed dynamics when the observation length scale is decreased is discussed in terms of the synchronization of small-scale events.

Mots clés: Dislocation dynamics; Acoustic methods; Self-organization; Portevin-Le Chatelier effect; Synchronization

Domaines: Mécanique des matériaux [physics.class-ph]

M.A. Lebyodkin, N.P. P Kobelev, Y. Bougherira, Denis Entemeyer, C. Fressengeas, et al.. On the similarity of plastic flow processes during smooth and jerky flow: Statistical analysis. Acta Materialia, 2012, 60 (9), pp.3729-3740. ⟨10.1016/j.actamat.2012.03.026⟩. ⟨hal-02173954⟩