The need for a decarbonized energy transition encourages the growth of the hydrogen industry in France and elsewhere, which creates an increasing demand for the durability of metallic materials in a hydrogenated environment. The presence of hydrogen in metallic materials increases embrittlement and contributes to premature failure. Numerous studies in the literature seek to understand the relationship between hydrogen, microstructure, and mechanical properties (1). These studies frequently focus on volume properties. Alternatively, the surface, which has received less attention, serves as a barrier between the reactive environment and the material in the vast majority of cases. Here, we propose to investigate the impact of surface morphology, down to nanometer scales, on hydrogen absorption. A better understanding of the key parameters may allow for surface functionalization in order to reduce hydrogen intake. Thus, femtosecond laser texturations are performed on the surface of metallic samples to create various surface topographies (2,3). The absorption of hydrogen in textured samples will then be analysed using electrochemical permeation and thermal desorption spectroscopy after electrochemical pre-charging. Therefore, the influence of various rugosity parameters allows for the establishment of a link between hydrogen absorption capacity and surface morphology. Accordingly, our goal is to create self-organized nanostructures with a high aspect ratio, allowing for significant surface modification. In addition, local Kelvin probe analyses will be carried out in order to establish a link between topography and hydrogen local absorption. Most analyses will be conducted on a ferritic iron-chromium alloy.
References:
- M. Alnajjar et al.: Mater. Sci. Eng., A 785, 139363 (2020)
- A. Nakhoul et al.: Nanomaterials 11, 1020 (2021)
- A. Nakhoul et al.: Adv. Sci. 9, 2200761 (2022)
