In-Situ Spatially Resolved Characterization of Stress-Affected Corrosion Kinetics
Abstract
Operational readiness is a priority across the Department of Defense (DoD) platforms. The cost of corrosion in DoD was estimated in2002 to be in the order of $20 billion to repair the damage to military equipment and infrastructure. Moreover, corrosion does not only impact the DoD budget, but also significantly affects military readiness and the safety of military personnel. It was found that in military aircraft, almost 80% of cracks initiate close to corrosion sites, e.g., around fastener locations, and frequently the cause is galvanic corrosion. The reaction kinetics, as opposed to considering a purely thermodynamic aspect, have been identified asthe controlling factors in these corrosion systems. However, these reaction rates have generally been measured in stress/strain-free environments, in contrast to the exposures seen in flight operations. The information gained from this research can feed structural life management tools to better track material damage for more efficient maintenance schedules and will ultimately enable predictive damage models. This ONR DURIP proposal will enhance the research activities related to stress affected corrosion kinetics and other projects funded by the DoD, the Office of Naval Research, the US Air Force Academy, and the Department of Energy.The investigating team from the University of Texas at San Antonio (UTSA) seeks to develop an integrated system that will enable spatially resolved measurements of strain-induced misorientation evolution, crystallographic information, plastic localization, lattice rotation, residual stresses, and phase instability. For this purpose, funds are sought for the purchase of an i) electron backscatter diffractometer (EBSD), ii) a nanomechanical testing system, and iii) a sample transfer suitcase that will preserve the characteristics of the in-situ produced oxide when needed. This system will enable spatially resolved metallurgical and in-situ mechanical characterization, which is a capabilitycurrently absent at UTSA that will improve the research and education of students, scientists, and engineers in areas important to national defense. Furthermore, the system will be institutionalized through the integration with the general UTSAcore facility Kleberg Advanced Microscopy Center (KAMC) and will be open to all faculty and students.UTSA is a proud Hispanic Serving Institution (HSI) as designated by the U.S. Department of Education. Approximately 60% of the UTSA student body belongs to a minority group, and 45% of the students are designated as first-generation college students. UTSA is also a proud 2020 recipient of the Seal of Excelencia in education. These settings provide a suitable environment and opportunities to educate minority students through research to build a diverse future workforce in Corrosion, which is a discipline important to DoD missions. The equipment acquisition described herein is anticipated to have a significant impact in 1) Education and Curricula;2) Research and Training; 3) promoting Diversity and Attracting Minority students; and 4) existing STEM programs at UTSA. This proposal aims to acquire an integrated system with EBSD and nanomechanical testing capabilities that will enable the analysis of the micro- and nano- crystallographic information, and the mechanical testing of samples under a variety of loading scenarios to advance the understanding of the mechanisms behind stress-affected corrosion kinetics. This capability will enable spatially resolved measurements of key important quantities via state-of-the-art metallurgical and mechanical characterization methods.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- May 15, 2023
- Source ID
- N000142312516
Entities
People
- Brendy Rincon Troconis
Organizations
- Office of Naval Research
- United States Navy
- University of Texas at San Antonio