In situ observation of liquid metal dealloying and etching of porous FeCr by X-ray tomography and X-ray diffraction

Morgane Mokhtari (1) , Christophe Le Bourlot (1) , Jérome Adrien (1) , Anne Bonnin (2) , Wolfgang Ludwig (1, 3) , Pierre-Antoine Geslin (1) , Takeshi Wada (4) , Jannick Duchet-Rumeau (5) , Hidemi Kato (4) , Eric Maire (1)

1 MATEIS - Matériaux, ingénierie et science [Villeurbanne]
2 SLS-PSI - The Swiss Light Source (SLS)
3 ESRF - European Synchrotron Radiation Facility [Grenoble]
4 School of Engineering [Tohoku Univ]
5 IMP - Ingénierie des Matériaux Polymères

A liquid metal dealloying mechanism is investigated in situ using X-ray tomography and X-ray diffraction. While immersing a FeCrNi precursor alloy in a molten Mg bath, a selective dissolution of Ni atoms into the Mg bath occurs leading to FeCr atom rearrangement. At room temperature, after cooling down, a bicontinuous structure of FeCr and a solid solution of Ni in Mg is obtained. A final etching step is used to remove the Mg solid-state solution phase and form microporous FeCr. 3D dealloying and etching kinetics can be measured using X-ray tomography reconstruction. The evolution of relative strain is analyzed from X-ray diffraction patterns. The different behavior observed during dealloying and etching, depending on the precursor composition is discussed.

Domaines: Matériaux

Morgane Mokhtari, Christophe Le Bourlot, Jérome Adrien, Anne Bonnin, Wolfgang Ludwig, et al.. In situ observation of liquid metal dealloying and etching of porous FeCr by X-ray tomography and X-ray diffraction. Materialia, 2021, 18, pp.101125. ⟨10.1016/j.mtla.2021.101125⟩. ⟨hal-03507573v2⟩