Measurement of lattice rotations and internal stresses in over one hundred individual grains during a stress-induced martensitic transformation

Younes El Hachi (1, 2) , Benoit Malard (2) , Sophie Berveiller (1) , Jonathan Wright (3)

1 LEM3 - Laboratoire d'Etude des Microstructures et de Mécanique des Matériaux
2 CIRIMAT - Centre interuniversitaire de recherche et d'ingenierie des matériaux
3 ESRF - European Synchrotron Radiation Facility

To better understand the properties of polycrystals at a microscopic scale during cyclic mechanical loading we have measured the relationship between grain orientations, their positions inside the sample and their internal stresses. In this work, in-situ 3DXRD technique was performed on over hundred grains during the stress-induced martensitic transformation in a Cu-Al-Be shape memory alloy. Information about the position, orientation, and stress field was obtained for each austenitic grain. These results have been used to develop a procedure that allows automatic processing for a large number of grains, matching them during loading and leads to a quantitative stress field. A strong heterogeneity of stress state between the grains at the surface and in the volume is evident

Domaines: Physique [physics]

Younes El Hachi, Benoit Malard, Sophie Berveiller, Jonathan Wright. Measurement of lattice rotations and internal stresses in over one hundred individual grains during a stress-induced martensitic transformation. 10th European Symposium on Martensitic Transformations (ESOMAT), Sep 2015, Antwerp, Belgium. ⟨10.1051/matecconf/20153302003⟩. ⟨hal-01572815⟩