Combining AFM imaging and elementally resolved spectroelectrochemistry for understanding stability and quality of passive films formed on Alloy 600. Issue 6 (4th January 2022)

• Record Type: Journal Article
• Authors: Dworschak, Dominik; Bishara, Marina; Cheng, Hsiu‐Wei; Valtiner, Markus
• Is Part Of: Materials and corrosion. Volume 73:Issue 6(2022)
• Page Start: 842
• Page End: 850
• Publication Date: 2022-01-04
• Subjects: electrochemical AFM -- electrochemical ICP‐MS -- nickel base alloys -- passivation -- pulse voltammetry; Materials -- Periodicals; Metals -- Periodicals; Corrosion and anti-corrosives -- Periodicals; 620.1122305
• DOI: 10.1002/maco.202112984
• Languages: English
• ISSNs: 0947-5117

Abstract

Abstract: Understanding elemental corrosion currents and visualizing corroding topographies provides a detailed insight into corrosion mechanisms at the nanoscale. Here, we develop a strategy to understand the elemental composition, corrosion resistivity, and local stability of passive materials. Specifically, we utilize a pulse voltammetry approach in a novel electrochemical atomic force microscopy (AFM) cell and complement this data by real‐time dissolution currents based on spectroelectrochemical online analysis in an inductively coupled plasma mass spectroscopy (ICP‐MS) flow cell. We study the oxide properties and their protective behavior when formed under different applied potentials using Alloy 600 as a model sample. Both AFM and ICP‐MS data show that passive films formed on Alloy 600 at around +0.3 to +0.4 V in neutral 1 mM NaCl solution are most stable during anodic corrosion at +1.0 V, while AFM further demonstrates that local dissolution occurs, indicating locally varying defect levels in the passive film. In combination with both techniques, our approach provides real‐time elementally resolved and localized information of passive film quality under corrosive conditions, and it may prove useful for other corroding materials. Abstract : Elemental corrosion currents and visualized corroding topographies provide in combination a detailed insight into corrosion mechanisms at the nanoscale. Using a pulse voltammetry approach in an electrochemical atomic force microscopy cell and with a spectroelectrochemical inductively coupled plasma mass spectroscopy flow cell, oxide properties and protective behavior of passive films formed on Alloy 600 under different potentials are studied.