Nowadays several measuring techniques, like SVET, SRET and Kelvin probe, exist to study local potential differences on alloys surfaces. One very sensitive technique with good spatial resolution is scanning Kelvin probe force microscopy. This technique enables direct measurement of the local Volta potential differences resulting from very complicated microstructures due to the thermal history of the produced aluminium alloys. In combination with SEM, EDS and electrochemical techniques detailed mechanistic studies on the relation between the microstructure and the corrosion behaviour have now become possible. Local electrochemical measuring techniques do show that local Volta potential differences in many cases are clearly reflected in local corrosion behaviour.