Strain localization and damage mechanisms during bending of AA6016 sheet

Mattei, Laurent; Daniel, Dominique; Guiglionda, Gilles; Klöcker, Helmut; Driver, Julian

Affiliations

¹Ecole Nationale Supérieure des Mines de Saint-Etienne, 158 Cours Fauriel, 42000 Saint-Etienne, France

²Constellium, Centre de recherches de Voreppe, 725 rue Aristide Bergès, BP 27, 38341 Voreppe Cedex, France

Abstract and keywords

The bendability of AA6016 sheets is a critical parameter for many automotive applications. In this experimental study the origins of damage and its evolution are characterized using interrupted and in-situ bending tests to correlate microstructural evolution with damage development. Local strains were estimated by optical and scanning microscopy (EBSD). Together with the load-displacement plots, they provided a set of physical parameters characterizing crack initiation. In particular, it is shown that

crack initiation occurs at the maximum of the rigidity–displacement curve;
cracking is preceded by strain localization in the form of macro-shear bands which induce surface roughening. Local necking then occurs in some surface grains and leads to ductile intergranular crack propagation.

The sequence of microscopic changes at the grain scale up to and beyond crack initiation have been characterized and quantified in terms of local grain strains, coarse intragranular slip and shear band evolution over several grains.

Keywords: Aluminum alloys; Bendability; Damage kinetics; EBSD and optical observations

Links

DOI: 10.1016/j.msea.2012.09.028

WoS: 000312623600107

History

Received: 2012-06-21

Revised: 2012-09-06

Accepted: 2012-09-07

Online: 2012-09-16

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Cited By (8)

Year	Entry
2019	Muhammad W, Ali U, Brahme AP, Kang J, Mishra RK, Inal K. Experimental analyses and numerical modeling of texture evolution and the development of surface roughness during bending of an extruded aluminum alloy using a multiscale modeling framework. Int J Plast. June 2019;117:93-121.
2013	Mattei L, Daniel D, Guiglionda G, Moulin N, Klöcker H, Driver J. Grain scale modeling of the bendability of AA6XXX Al alloy sheet. Mater Sci Eng. October 20, 2013;A583:96-104.
2019	Muhammad W, Kang J, Brahme AP, Ali U, Hirsch J, Brinkman H-J, Engler O, Mishra RK, Inal K. Bendability enhancement of an age-hardenable aluminum alloy, I: relationship between microstructure, plastic deformation and fracture. Mater Sci Eng. April 10, 2019;A753:179-191.
2019	Muhammad W, Brahme AP, Ali U, Hirsch J, Engler O, Aretz H, Kang J, Mishra RK, Inal K. Bendability enhancement of an age-hardenable aluminum alloy, II: multiscale numerical modeling of shear banding and fracture. Mater Sci Eng. April 29, 2019;A754:161-177.
2020	Lu G, Wang J, Liu Y, Liu C. Effect of heating rate during solution treatment on the bendability of Al–Mg–Si alloys. Mater Sci Eng. July 22, 2020;A791:139604.
2021	Li Z, Zhang Z, Zhou G, Zhao P, Jia Z, Poole WJ. The effect of mg and si content on the microstructure, texture and bendability of Al–Mg–Si alloys. Mater Sci Eng. May 13, 2021;A814:141199.
2022	Yoo YSJ, Su Y, Das S, Hamerton R, Kacher J. Multiscale electron microscopy investigation of grain boundary-mediated crack initiation in AA6451 during three-point bending. Mater Sci Eng. January 26, 2022;A833:142572.
2015	Liimatainen M. The Effect of Microstructure on Bendability of Ultra-High Strength Steels [Master's thesis]. Tampere University of Technology; March 2015.