Oxide Fracture by Indentation to Measure Repassivation Kinetics
EMSL Project ID
1811
Abstract
Many corrosion resistant materials, such as titanium and stainless steels, owe much of their corrosion resistance to the presence of a very thin passive film which isolates the metal from the surrounding environment. This film, which can be as thin as 10 or 20 atoms, may be damaged during service, and must re-form to repassivate the metal and continue to provide corrosion protection. While the film is re-forming, there is a current flow that corresponds to the amount of metal dissolution. This project describes a novel testing method for measuring the repassivation kinetics of corrosion resistant engineering alloys, the indentation induced film fracture test (IIFF), and a proposed course of study to experimentally verify the technique. The specific objectives are to Identify: oxide fracture events in titanium and aluminum during indentation in ambient conditions using well annealed polycrystalline materials; conditions for oxide fracture during potentiostatically controlled indentations; and to monitor current decay from events. The IFF experiments are being carried out at WSU using a Hysitron Triboscope and the associated electrochemical polarization equipment. However, it is highly desirable to characterize the film structure and chemistry. There is a dramatic difference in the film strength of anodically grown TiO2 films grown at various rates, between 1 mV/s and 10 V/s. Therefore, we propose utilizing characterization methods not readily available at WSU for determining both the structure and composition of films which have been tested using the IFF method to make determine the classical relationships between processing conditions, structure, and resulting properties. It would be highly desirable to perform the characterization work a few times during the course of the project so that we could refine our testing at WSU to investigate any particularly interesting results found with the EMSL facilities.
Project Details
Project type
Exploratory Research
Start Date
2003-11-18
End Date
2000-12-31
Status
Closed
Released Data Link
Team
Principal Investigator
Related Publications
Darian N. Smercina, Young-Mo Kim, Mary S. Lipton, Dusan Velickovic, Kirsten S. Hofmockel. 2022. "Bulk and Spatially Resolved Extracellular Metabolome of Free-Living Nitrogen Fixation." Applied and Environmental Microbiology 88 (12) 10.1128/aem.00505-22