Two mechanisms for the normal and inverse behaviors of the critical strain for the Portevin–Le Chatelier effect

Spatio-temporal characteristics of plastic instability in AA5182-O during biaxial deformation

“…7b. Fu et al [39] reported that the stress drop (or serration amplitude) in an AA5456 alloy increased as tensile strain increased and maintained a constant saturated value after a strain of $0.15 at 273 K and 298 K. Their conclusion was that the stress drop was not sensitive to strain at other temperatures. In Fig.…”

Study on the out-of-plane deformation of the Portevin–Le Chatelier band by using digital shearography

“…2(a), serration yielding in the stress curve is present at 50 s. Due to the low concentration of solute atoms (Mg), the serration amplitude is much smaller than that in type 5456 [10] and 2017 Al alloys [28]. In this study, we chose a range of 250-280 s to investigate the PLC band in detail.…”

“…This phenomenon is characteristic of serration yielding in stress-strain curves and localized deformation bands (PLC bands) in the sample. The PLC effect is generally explained by dynamic strain aging (DSA) [6][7][8][9][10], i.e., the dynamic interaction between mobile dislocations and solute atoms. When mobile dislocations are temporarily arrested at obstacles, the solute atoms diffuse to and pin them.…”

Influences of Initial Microstructures on Portevin‐Le Chatelier Effect and Mechanical Properties of a Ni–Fe–Cr–Base Superalloy

“…In order to distinguish the features of stress variations, some types of serrations have been classified, which are associated with the morphologies of stress serrations . Meanwhile, some investigators also found the normal and inverse PLC effects during hot deformation, and gave the reasonable explanations or interpretations on deformation mechanisms . For example, the dynamic strain aging (DSA) model, which relates to the consequences of diffusing solute atoms toward mobile dislocations, is a commonly accepted micro‐mechanisms .…”