This program is to probe nanoscale oxidation properties of metals under applied stresses by coupling mechanical loading and gas-surface reactions within a specialized in situ environmental TEM, while simultaneously monitoring the structural and chemical changes during the oxidation. This program will examine: 1) effect of applied stress on nucleation and growth of oxide islands; 2) correlations between applied stress and nanoscale morphologies of oxide islands; and 3) effect of applied stress on the coalescence behavior of oxide islands. The outcome of the study will provide the foundation for constructing atomistic oxidation models by taking into account environment effects, which are no longer described by the atmosphere only, but by all kinds of constraints (e.g. mechanical and thermal) an engineering component may undergo. In addition to addressing these scientific issues, the study will also have significant practical implications as dimensions of engineered systems continue to shrink to nanoscale.
Because the project addresses fundamental issues that help understand nanoscale correlations of surface structure, reactivity, mass transport, and surface morphology with applied stresses, these studies will broadly impact on many fields including high temperature oxidation, corrosion, electrochemistry, thin film processing, heterogeneous catalysis, and fuel cells, where the prototypes of basic processes also occur. As part of this research program, students at the graduate and undergraduate levels will be involved in learning about state-of-the-art electron microscopy techniques and materials issues that are at the forefront of current materials research. This project will involve broad collaborations with scientists at other institutions and in industry, which will provide students outstanding opportunities to see a variety of research environments and help them discover future career opportunities in industry or academia.