|About this Abstract
|MS&T23: Materials Science & Technology
|Grain Boundaries, Interfaces, and Surfaces: Fundamental Structure-Property-Performance Relationships
|Disordered Interfaces in Nanocrystalline Al-Ni-Ce: Origins of Microstructural Stability and Mechanical Performance
|Glenn H. Balbus, Johann Kappacher, David J. Sprouster, Fulin Wang, Jungho Shin, Yolita M. Eggeler, Timothy J. Rupert, Jason R. Trelewicz, Daniel Kiener, Verena Maier-Kiener, Daniel S. Gianola
|On-Site Speaker (Planned)
|Glenn H. Balbus
Nanocrystalline metals – metals with grain sizes less than 100 nm – are prime candidate materials for extreme environments due to properties imbued by their high density of grain boundaries. While these ubiquitous grain boundaries underpin their high strength, nanocrystalline metals often exhibit grain boundary mediated instabilities such as catastrophic shear localization and rapid microstructural coarsening. In this talk, I will discuss an emerging strategy to overcome these intrinsic grain boundary instabilities: the incorporation of disorder at interfaces via multicomponent alloying. We investigate the effects of local chemistry and structure on the thermal and mechanical behavior of a nanocrystalline Al-Ni-Ce alloy via nanoindentation, ultrafast calorimetry, synchrotron X-ray scattering, and in situ electron microscopy. Our results demonstrate that the alloy investigated exhibits exceptional thermal stability, promising elevated temperature mechanical properties, and tunable shear localization behavior, all owing to the complex chemical and structural evolution of disordered grain boundaries.