Color maps of the current from the CMEA arranged in a fastener geometry over the 10,000 s full immersion in 0.6 M NaCl solution with a small gap of (∼100 μm) between the AA7050 and the steel fastener. (a) shows the color maps at a higher current scale than (b). Red indicates positive currents (net anodic), blue indicates negative currents (net cathodic), and white indicates zero current (electrodes with a net galvanic current close to zero).