MURI Home Page   Aqueous Corrosion

The target of this task is to understand in detail the fundamental processes in aqueous corrosion from atomic to macroscopic electrochemistry. We seek to answer and build upon the following scientific questions:

  1. What is the structure-compositional profile across the metal/oxide interface, is there atomic-scale segregation, faceting and how does this alter the energetics and local electrochemical potentials?
  2. What is the structure-composition profile across the interfaces and does this affect the concentration profiles in adjacent regions?
  3. How does the phase stability, nucleation and growth of oxide and corrosion of the alloy vary with respect to local variations in chemical potentials and pH?
  4. What is it about dopants in alloys changing aqueous corrosion, is it changes in the Fermi energy of the oxide and/or does segregation and diffusion matter?

Our strategy is multipronged. We first need to establish the base structure, thermodynamics and local chemical distributions of the material by synergistic experiments and theory. These will then form the basis for combining experimental data on local and grain-boundary specific corrosion with modeling. Our vision is to generate grain-boundary and interface specific Pourbaix diagrams and similar by combining multiple levels of materials theory and computational methods to explain experimental local corrosion processes from the atomic scale in detail. Site-specific electrochemical equilibria phase information with nucleation rates offers a significant advance, forming the basis for future design of better performing materials by determining which microstructural features need to be controlled.