|About this Abstract
||2011 TMS Annual Meeting & Exhibition
||Surfaces and Heterostructures at Nano- or Micro-Scale and Their Characterization, Properties, and Applications
||Mechanical Properties of Grain Boundary-Containing Al Nano-Pillars
||Allison Kunz, Siddhartha Pathak, Andrew Jennings, Julia R Greer
|On-Site Speaker (Planned)
Mechanical behavior of bi-crystalline aluminum nano-pillars under uniaxial compression reveals size effects, stochastic stress-strain signature, and strain-hardening. Pillar diameters range from 400nm to 2 microns and contain a single high-angle grain boundary oriented parallel to pillar axes. Loading-unloading cycles reveal no Bauschinger effect, suggesting that the native oxide does not trap mobile dislocations. Our results indicate that these bi-crystalline pillars are characterized by intermittent strain bursts and exhibit an identical size effect to their single crystalline counterparts. Further, we find that the presence of the grain boundary generally decreased the degree of work hardening relative to the single-crystalline micro-pillars. These findings suggest that micro-pillar plasticity in the presence of a grain boundary is also dislocation nucleation-controlled and that the grain boundary likely serves as a dislocation sink rather than a dislocation source. Transmission electron microscopy (TEM) analysis provides further insight into dislocation density evolution in these bicrystalline pillars.
||Planned: A CD-only volume