Reactive forcefield developments for studying cathodic reactions on modified Cr2O3 surfaces
Abstract
Controlling corrosion at galvanic junctions between aluminum alloys and stainless steel fasteners is essential for engineering airframe structures. Cathodic reduction reactions are a limiting factor for corrosion under atmospheric conditions, and the salient mechanisms at these junctions appear to be governed by oxygen reduction reaction (ORR) catalysis on stainless steel, but how and why this happens remains unknown. We hypothesize that ORR sites on chromium oxide layers at the solid/liquid interface of austenitic stainless steels will form due to a variety of atomic scale environmental factors. These factors include a) ORR active sites forming at metals in the stainless steel (e.g. Fe, Ni, and Mo) diffusing through non-crystalline regimes to the solid/liquid interface, and b) water and other ions (e.g. chloride) contributing to ORR site formation by binding to the surface. To test this hypothesis, we will develop parameter sets for ReaxFF potentials that are expected to be more well-suited for studying atomic scale mechanisms at solid/liquid interfaces of complex solids and liquids. The project plan objectives are: Months 1–9: Extend our current developments and validations of ReaxFF potentials for Cr/Fe/O/H/Cl systems to include Ni and Mo parameters. Months 10–15: Apply these parameterized models in atomistic simulations to study how nickel and molybdenum impact cathodic oxygen reductions and the role of chlorine. In sum, this study will result in a new computational tool to help expedite atomic scale modeling of electrochemical interfaces and thus a framework for simulating and interpreting polarization curves, as well as provide better fundamental understanding how to control cathodic reactions on stainless steel. Thus, the project would contribute to enhancing the performance, affordability, and reliability of corrosion-resistant airframe structures and materials for the Navy.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Feb 10, 2025
- Source ID
- N001732510040
Entities
People
- John A. Keith
Organizations
- United States Naval Research Laboratory
- United States Navy
- University of Pittsburgh