Hydrogen embrittlement of aluminum in aqueous environments examined by in situ electrochemical nanoindentation

The hydrogen effect on the mechanical properties of aluminum was studied using an in situ electrochemical nanoindentation setup. The adsorption of hydrogen ions at the open circuit potential in a solution at pH 6 (less than the isoelectric point = 9.5) resulted in a change of pop-in load. Similar behavior was observed in a solution at pH 9 under cathodic polarization. The change in pop-in load is attributed to the hydrogen-induced reduction of cohesive energy and hydrogen segregation on dislocations.