Sub-micrometre imaging of metal surface corrosion by scanning Kelvin nanoprobe

Abstract

The detection of the initial changes in the surface microstructure and local chemical properties connected to the corrosion process is possible using a high-resolution scanning Kelvin nanoprobe. This technique provides the simultaneous imaging of the topographical features and potential distribution across a surface at the sub-micrometer level. Nanoprobe measurements performed on samples of Al, Cu, Fe, Ni, Ag and Pt before and after exposure to different corroding solutions reveal the significant changes that take place during the first stages of the corrosion process. The similarities of the images obtained subsequent to corrosion are reflective of surface fractal behavior.