SEM in-situ tests for the study of the deformation mechanisms in a duplex stainless steel obtained by Additive Manufacturing
12 MONTHS, Remunerated
Ecole polytechnique, Palaiseau (91)
The objective of the post-doc proposed by the LMS (Laboratoire de Mécanique des Solides, École Polytechnique) is an experimental analysis of the elastoplastic properties of a superduplex stainless teel SAF2507 under monotonic and/or cyclic tensile loading based on SEM in-situ tests. We will be particularly interested in:
• The role of the austenitic and ferritic phases on the deformation mechanisms,
• The effect of the phase contents, depending on the heat treatment after AM,
• The effect of the process (L-PBF versus DED) for the same phase content
To carry out this work, micromechanical tests under SEM will make it possible to observe the deformation mechanisms in the case of monotonic and/or cyclic tensile loading, as they have been carried out in recent works in AM, but also for two-phases alloys. In this aim, small size specimens will be extracted from plates and cylinders already manufactured at ISAE SupAero. Different marking techniques are employed at different scales to perform High Resolution Digital Image Correlation (HR-DIC). Strain fields are analysed regarding the microstructure (grains, GB, phases) thanks to EBSD in order to understand local deformation mechanisms and to give information for the crystal plasticity-based simulations realized by other project partners.