Investigation of Kelvin probe force microscopy efficiency for the detection of hydrogen ingress by cathodic charging in an aluminium alloy

Detecting and locating absorbed hydrogen in aluminium alloys is necessary for evaluating the contribution of hydrogen embrittlement to the degradation of the mechanical properties for corroded or cathodically hydrogen-charged samples. The capability of Kelvin probe force microscopy (KFM) to overcome this issue was demonstrated. Aluminium alloy samples were hydrogenated by cathodic polarization in molten salts (KHSO4/NaHSO4·H2O). The presence of absorbed hydrogen was revealed; the affected zone depth was measured by secondary ion mass spectroscopy analyses and KFM measurements.