Defects producing formation of micro-cracks in aluminum during electrochemical charging with hydrogen

The formation of micro-cracks in high purity aluminum during electrochemical charging by hydrogen was studied. The experiments reveal that, in aluminum samples, a wide distribution of hydrogen bubbles on the surface (blisters) and under the surface into the volume, were produced during electrochemical charging. This phenomenon can lead to the formation of micro-cracks in the absence of externally applied stress. Examination of electrochemically charged samples by transmission electron microscopy (TEM) showed micro-cracks with a typically ductile mode of fracture.