Skip to Main content Skip to Navigation
Journal articles

Role of Self-Organization of Dislocations in the Onset and Kinetics of Macroscopic Plastic Instability

Abstract : The present paper examines two aspects of the problem of critical conditions of jerky flow in alloys, or the Portevin-Le Chatelier (PLC) effect. Recent development of dynamic strain aging (DSA) models proved their capacity to qualitatively reproduce complex non-monotonic behavior of the critical strain, providing that the parameters of theory are allowed to depend on strain. Experimental measurements of such strain dependences have been realized for the first time and used to revise the predictions of the critical strain and stress relaxation kinetics upon abrupt strain-rate changes. On the other hand, it is usually omitted from consideration that the PLC stress serrations can last very short time in comparison with the characteristic time of stress transients. The development of stress drops was studied with the aid of the acoustic emission (AE) technique. It is shown that such macroscopic instabilities are caused by clustering of AE events which otherwise occur all the time, including the periods of smooth plastic flow. The role of synchronization of dislocation avalanches in the development of abrupt stress serrations and its relationship with the predictions of the local DSA models is discussed.
Document type :
Journal articles
Complete list of metadata

https://hal.univ-lorraine.fr/hal-03256672
Contributor : Jérôme Slowensky <>
Submitted on : Thursday, June 10, 2021 - 1:43:33 PM
Last modification on : Friday, June 11, 2021 - 9:27:36 AM

Identifiers

Citation

Nikolay Kobelev, Mikhail Lebyodkin, Tatiana Lebedkina. Role of Self-Organization of Dislocations in the Onset and Kinetics of Macroscopic Plastic Instability. Metallurgical and Materials Transactions A, Springer Verlag/ASM International, 2017, 48, pp.965-974. ⟨10.1007/s11661-016-3912-x⟩. ⟨hal-03256672⟩

Share

Metrics

Record views

12