Hydrogen mapping in an aluminum alloy using an alternating current scanning electrochemical microscope (AC-SECM)

Manon Chloé Lafouresse (1) , Marie-Laëtitia De Bonfils - Lahovary (1) , Lydia Laffont-Dantras (1) , Christine Blanc (1)

1 CIRIMAT - Centre interuniversitaire de recherche et d'ingenierie des matériaux

Measurements using an alternating current scanning electrochemical microscope (AC-SECM) were performed on a 2024 aluminum alloy pre-charged with hydrogen. A gradient in AC current magnitude was observed over several hundreds of microns on the side perpendicular to the charging side. After heat treatment at 130 °C for 2 h, the current gradient disappeared. Comparison with scanning Kelvin probe force microscopy (SKPFM) measurements confirmed that the increase in AC current magnitude observed with AC-SECM was due to the presence of hydrogen in the material. Fitting of localized impedance spectra with a suitable equivalent circuit showed the influence of H on the corrosion rate. AC-SECM is thus a powerful new method to detect hydrogen and study its effect on corrosion at the micrometer scale.

Mots clés: Aluminum alloys; Hydrogen absorption; Hydrogen desorption; Scanning Kelvin probe force microscopy (SKPFM); Alternating current scanning electrochemical microscopy (AC-SECM)

Domaines: Matériaux; Science des matériaux [cond-mat.mtrl-sci]; Génie des procédés; Matériaux

Manon Chloé Lafouresse, Marie-Laëtitia De Bonfils - Lahovary, Lydia Laffont-Dantras, Christine Blanc. Hydrogen mapping in an aluminum alloy using an alternating current scanning electrochemical microscope (AC-SECM). Electrochemistry Communications, 2017, vol. 80, pp. 29-32. ⟨10.1016/j.elecom.2017.05.007⟩. ⟨hal-01579434⟩