Macroscopic consequences of Piobert–Lüders and Portevin–Le Chatelier bands during tensile deformation in Al-Mg alloys

Baptiste Reyne (1) , Pierre-Yves Manach (2) , Nicolas Moes (3)

1 ECN - École Centrale de Nantes
2 LIMATB - Laboratoire d'Ingénierie des Matériaux de Bretagne
3 GeM - Institut de Recherche en Génie Civil et Mécanique

Lüders bands and the Portevin-Le Chatelier effect are both due to plastic flow instabilities that affect a wide variety of metallic materials. The present study focuses on understanding these behaviors. Field kinematic measurements combined with the comparison of two specimen sizes are used here to characterize the Al-Mg alloy AA5086, by investigating the kinetics of individual localization bands. A unifying point of view is proposed for the classification of these bands together with the identification of a constitutive relation linking strain increments and nucleation stress, as well as evidence of the factors determining the development of serration behaviors. This leads to a novel interpretation of the spatiotemporal behavior of the bands as being the result of a competition between the influence of plastic strain and its gradient.

Mots clés: strain localization; Piobert-Lüders; characterization; Portevin-Le Chatelier; plasticity; aluminium alloys

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

Baptiste Reyne, Pierre-Yves Manach, Nicolas Moes. Macroscopic consequences of Piobert–Lüders and Portevin–Le Chatelier bands during tensile deformation in Al-Mg alloys. Materials Science and Engineering: A, inPress, 746, pp.187-196. ⟨10.1016/j.msea.2019.01.009⟩. ⟨hal-01976350⟩