Periodic laser surface texturing limits hydrogen permeation in Fe-Cr alloy

Ultrafast laser-induced periodic surface structures (LIPSS) represent a significant advancement in reducing hydrogen uptake during the cathodic charging of Fe-Cr alloy. This study evaluates the physico-chemical impact of low and high spatial frequency laser texturing (LSFL and HSFL) on mirror-like surfaces, which demonstrate substantial decreases in hydrogen subsurface concentration. Advanced analyses that ultrafast laser-induced periodic surface structures, despite having a similar oxide layer thickness to mirror surfaces, exhibit a significantly different oxide composition. These changes in surface oxidation induced by laser texturing play a pivotal role in mitigating hydrogen absorption. Morrobrt, Atomic Force Microscopy (AFM) also reveals that these topographical variations, influenced by skewness and kurtosis, play a significant role in reducing hydrogen permeation