Validity of crystal plasticity models near grain boundaries: a contribution of elastic strain measurements at the micron scale

• Main Authors: Plancher, Emeric, Tajdary, Pouya, Auger, Thierry, Castelnau, Olivier, Favier, Véronique, Loisnard, Dominique, Marijon, Jean-Baptiste, Maurice, Claire, Michel, Vincent, Robach, Odile, Stodolna, Julien
• Format: Journal Article
• Language: English
• Published: 04-11-2019
• Subjects: Physics - Classical Physics; Physics - Materials Science
• DOI: 10.48550/arxiv.1911.07636

Journal of Materials Science, Springer Verlag, 2019, 71 (10),
pp.3543-3551 Synchrotron Laue microdiffraction and Digital Image Correlation measurements
were coupled to track the elastic strain field (or stress field) and the total
strain field near a general grain boundary in a bent bicrystal. A 316L
stainless steel bicrystal was deformed in situ into the elasto-plastic regime
with a four-point bending setup. The test was then simulated using finite
elements with a crystal plasticity model comprising internal variables
(dislocation densities on discrete slip systems). The predictions of the model
have been compared with both the total strain field and the elastic strain
field obtained experimentally. While activated slip systems and total strains
are reasonably well predicted, elastic strains appear overestimated next to the
grain boundary. This suggests that conventional crystal plasticity models need
improvement to correctly model stresses at grain boundaries.