Advanced experiments for characterizing and understanding hydrogen-assisted mechanical degradation

• Applicant: Professor Dr. Christian Motz, since 3/2019
• Subject Area: Mechanical Properties of Metallic Materials and their Microstructural Origins ; Synthesis and Properties of Functional Materials
• Term: from 2017 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 373150815

• Final Report Year: 2023

Final Report Abstract

In this work, methods for determining the local distribution of hydrogen in metallic materials were investigated and supplemented by micromechanical measurement methods. The focus was on the further development of the hydrogen detection method based on Scanning Kelvin Probe Force Microscopy. Its measurement signal correlates with the electrode potential of a metal-hydrogen electrode (and thus the concentration of hydrogen) which is formed in the system of sample, dissolved hydrogen and ambient humidity. The method was used and further developed in a separate in situ experimental setup to determine local hydrogen distributions at grain boundaries. In particular, the influence of the atmosphere (oxygen content and humidity) on the detected hydrogen was systematically investigated. Nanoindentation was additionally used to provide information on the local distribution of hydrogen by measuring mechanical properties on a small scale. Both measurement methods were performed successively on the same sample locations and the results about the local hydrogen distribution were compared with each other. The two measurement methods were supplemented by permeation tests and macroscopic and microscopic mechanical test series.

Publications

• Implementation of an experimental setup to qualitatively detect hydrogen permeation along grain boundaries in nickel using Scanning Kelvin Probe Force Microscopy under varying atmospheres. International Journal of Hydrogen Energy, 47(35), 15922-15932.
  Gruenewald, Patrick; Hautz, Niclas & Motz, Christian
  
• Kombination lokal aufgelöster Wasserstoff-Detektion und Name(n) der Kooperationspartnerinnen und –partner: zur mikromechanischer Prüfmethoden Untersuchung lokaler Wasserstoffversprödung, Dissertation, 2022, Universität des Saarlandes.
  P. Grünewald
  
• The effect of time dependent native oxide surface conditions on the electrochemical corrosion resistance of Mg and Mg-Al-Ca alloys. Corrosion Science, 212, 110925.
  Felten, Markus; Nowak, Jakub; Beyss, Oliver; Grünewald, Patrick; Motz, Christian & Zander, Daniela