EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

Despite a lot of research, hydrogen embrittlement mechanisms are still controversially discussed. Especially the role of plasticity itself is underestimated in many cases. Hence, the investigation of deformation processes under hydrogen influence is a vital field of research.
In-situ electrochemical nanoindentation became a versatile tool for probing the impact of electrochemical charging on the mechanical properties. Besides measuring hardness and Young’s modulus, deeper insights in the acting deformation mechanisms can be gained by advanced nanoindentation testing methods like nanoindentation strain rate jump tests.
The advantages and possibilities of this method are demonstrated on a precipitation hardened nickel-based alloy. In addition to the hydrogen-induced hardness increase, an increase in strain rate sensitivity and a decrease in activation volume was visible. The changes in plastic deformation related parameters could be related to short range effects, which can lead to a more localized deformation. Furthermore, the evaluation of the remaining imprints with laser scanning confocal microscopy showed a clear change in the evolution of the plastically deformed zone during hydrogen charging.