A new approach for in situ electrochemical nanoindentation: Side charging as a promising alternative

Publikationen: Beitrag in FachzeitschriftArtikelForschung(peer-reviewed)

Externe Organisationseinheiten

  • Forschungszentrum Jülich GmbH

Abstract

Understanding hydrogen embrittlement in metals is an essential task for the energy transition, where hydrogen plays a key role. Besides the economic consequences of embrittlement, safety aspects are a very important factor to consider. Therefore, materials need to be screened in order to evaluate their mechanical response under hydrogen influence. Besides macroscopic mechanical testing, in situ electrochemical nanoindentation and micromechanical testing —in general— represent promising methods as they allow to characterize individual microstructural features. In the established “front-side” charging approach, hydrogen enters the sample at the same surface on which indentation tests are performed. An alternative is “back-side” charging, where hydrogen is introduced at the opposite side of the indentation location. In the present study, a novel “side” charging cell was designed and the results were compared to those obtained by “front-side” charging. For this purpose, a ferritic steel with high chromium content (X6Cr17) underwent a grain coarsening heat treatment to ensure that multiple nanoindentation experiments can be performed within a single grain. A similar grain orientation was tested with both charging approaches. The novel “side” charging cell design outperforms the stiffness of the reference front-side charging cell by 60 %. Both cell designs yielded constant Young's moduli before, during and several hours after charging. The hardness increased during charging due to hydrogen uptake, whereas the hardness settled several hours after charging to the values before charging started. The presence of hydrogen at the indentation side was confirmed by in situ X-ray diffraction using a self-reporting titanium film.

Details

OriginalspracheEnglisch
Aufsatznummer120113
Seitenumfang9
FachzeitschriftActa materialia
Jahrgang276.2024
Ausgabenummer1 September
DOIs
StatusElektronische Veröffentlichung vor Drucklegung. - 14 Juni 2024