Simultaneous in situ time resolved SR-XRD and corrosion potential analyses to monitor the corrosion on copper

The focus of this study consists of examining how simultaneous SR-XRD and electrochemical measurements can provide information on the effectiveness of stabilization and storage treatments of copper artefacts in aqueous solution. The electrochemical cell used here was designed for in situ, time resolved SR-XRD studies of corrosion and inhibition studies on cultural heritage materials. Key objectives of the new cell were to monitor corrosion layers on alloys with realistic metallographic structures and to obtain co-incident, time resolved, electrochemical data such as reduction measurements, oxidation measurements and corrosion potential (E_corr) measurements. Here we present some early results from the cell. Firstly, a correlated SR-XRD and corrosion potential (E_corr) study of the reduction of nantokite during storage in sodium sesquicarbonate, which shows that the surface chemistry continues to change after E_corr has stabilized. Secondly, the use of X-ray data to identify specific changes occurring as a function of potential in the forced reduction of a more complex system.