Unusual behavior of the Portevin-Le Chatelier effect in an AlMg alloy containing precipitates

Stress serration patterns and kinematics of deformation bands associated with the Portevin-Le Chatelier effect in an Al-Mg alloy were investigated by analyzing the evolution of the applied stress and axial strain distribution. In contrast to usually observed strain localization behaviors, referring to propagating and static deformation bands at high and low strain rates, respectively, the propagation mode was found to persist in a wide strain-rate range. This unusual behavior is discussed in relation with the role of precipitates.