Ian McCue
Dept. of Materials Science and Engineering
Texas A&M University

Frontiers of Dealloying - Novel Processing for Advanced Materials

Location: EB1 Room 1011

Friday, September 30th 2016 - 11:00 am

Mechanical investigations demonstrate that smaller microstructural features yield stronger materials. There are numerous manifestations of this effect, including nanocrystalline polycrystals, nanolaminates, and single-crystalline micropillars and nanowires. However, there is a key challenge in assembling many nanoscale objects into a stable, defect-free material. I will describe work on fabricating bulk nanostructured metals using liquid metal dealloying (LMD). Dealloying is a self-organization process that relies on selective dissolution to produce morphologically complex structures with a well-defined feature size. LMD is analogous to electrochemical dealloying, but uses a liquid metal as the solvent. Using a combination of phase field modeling and experiments, I identify key kinetic parameters controlling pattern formation during dealloying. By tuning these parameters, we can fabricate structures with a variety of morphologies - globular, lamellar, and bicontinuous - and large breadth of length scales - 30 nm to 10 μm. I then examine the mechanical properties of these materials using Vickers microhardness, nanoindentation, and compression testing. Ongoing efforts to extend the dealloying design space and a potential commercial application will also be highlighted.

North Carolina State University