To investigate the role of intermetallic particles in the localised corrosion of AA7075‐T6, three particles were monitored over 16 h immersion in 3.5 wt% KCl solution. These were examined using Auger electron spectroscopy, energy dispersive X‐ray spectroscopy, scanning Kelvin probe force microscopy and focused ion beam‐scanning electron microscopy. Despite similar Volta potential measurements, the corrosion microchemistry varied significantly with composition. A Al7Cu2Fe intermetallic resulted in trenching while a (Al,Cu)6(Fe,Cu) intermetallic showed crevice corrosion and sub‐surface intergranular corrosion and a Al12Fe3Si intermetallic appeared to be galvanically inactive but showed crevice formation at the matrix interface and sub‐surface intergranular corrosion.

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Scanning Kelvin probe force microscopy has been employed to examine the behavior of second phase carbide particles in beryllium at different relative humidity levels and after exposure to deionized water. Carbides are believed to have a role in the localized corrosion of beryllium as a result of their hydrolysis when exposed at the metal surface. The presence of beryllium carbide was confirmed by means of Auger electron spectroscopy and the particles were further characterized by scanning electron microscopy, energy/wavelength dispersive X-ray spectroscopy and scanning Kelvin probe force microscopy. The particles were found to have a more noble Volta potential than the beryllium matrix and a decrease in the Volta potential difference between the second phase particles and the matrix was observed as the humidity was increased. A thick beryllium oxide/hydroxide layer then formed on the particles following exposure to water significantly reducing their potential.

Samples of S‐65 beryllium were vapour degreased using six chlorinated solvents and analysed by X‐ray photoelectron spectroscopy. Exposure to the solvent vapour is believed to result in the formation of inorganic chloride at the metal surface, which can act as a corrosion precursor. Exposure to chloroform, tetrachloroethene, pentachlorobenzene and chlorobenzene resulted in the greatest amounts of beryllium chloride formation (>0.8 at.%), while exposure to dichloromethane and 1,1‐dichloroethene produced the least (<0.5 at.%). Mechanical abrasion of the metal surface while submerged in chloroform resulted in a significant increase in inorganic chloride at the beryllium surface. Rinsing of the samples with distilled water, after exposure to solvent vapours, significantly decreased the amount of organic and inorganic chlorine on the samples but did not result in complete removal of these species. Copyright © 2016 John Wiley & Sons, Ltd.