Investigation of Metal Corrosion by In-Situ Electrochemical Force Microscopy

Abstract

Metal corrosion is a world-wide issue that affects millions of people and costs industries billions of dollars. In order to reduce the global impact of corrosion, new analyses must be conducted and new solutions must be created. In our current state, corrosion has been studied extensively at the macro level, but new technologies are emerging which permit the study of the corrosion process at much higher resolution – at a nanometer scale. This research project develops an in-situ characterization technique based on Atomic Force Microscopy (AFM) to take advantage of the ability to analyze the corrosion process at the nanoscale level in order to expand our knowledge of corrosion and suggest solutions to corrosion issues. With the researcher’s background in the automotive industry and interest in the aerospace industry, the research is catered to these industries by focusing on particular alloys.

AFM and Kelvin Probe Force Microscopy (KPFM), which involve both topographic and electric potential imaging – are used to study the corrosion of metallic samples in various electrolytes. SKPM is used to obtain voltapotential information about a surface and Contact AFM is used to obtain topographical information. Scanning Electron Microscopy (SEM) and Energy-Dispersive X-Ray Spectroscopy (EdS) are also used to obtain information about the chemical composition of the sample surface.

As a result, the characterization technique developed in this research will help understand the onset of corrosion and its link to voltage potentials and chemical composition, ultimately providing suggestions to industry for improving the integrity of a vehicle’s material composition. Topographical, electropotential, and chemical images embody the experimental results. Chemical images give insight to predict the initial nucleation of corrosion, whereas topographical and electropotential images characterize the corrosion process that occurs.

Conclusions regarding this research project are to be made with respect to the image results from AFM. Characterizations of the metal corrosion can be useful to automotive and aerospace companies for designing corrosion-resistant automobiles and aircraft. The ultimate goal of these conclusions is to suggest material selection, design, or composition to reduce corrosion.