|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Mechanical Behavior of Nanostructured Materials
||Experimental Observations of the Mechanical Behavior of Nanocrystalline Thin Films
||Kevin Hemker, Suman Dasgupta, Paul Rottmann
|On-Site Speaker (Planned)
Nanocrystalline metals are well known for their high strength and low ductility, but their response is not purely linear elastic. Dislocation motion is mitigated but not eliminated by the reduced grain size, and other deformation mechanisms can be activated and carry plastic deformation. Microtensile experiments of submicron freestanding nanocrystalline films have been coupled with TEM observations to elucidate the underlying deformation mechanisms. Mechanical and thermal stability, stress-induced grain boundary and twin boundary migration, dislocation activity and the role of impurities will be discussed. In particular, emerging in situ techniques such as TEM-based Precession Assisted Crystal Orientation Mapping (PACOM) now allow for nanoscale observations of individual grains and grain boundaries that provide quantitative mechanistic information about nanoscale deformation mechanisms. Key parameters of interest to this study include the effect of grain size and grain boundary misorientation, character and chemistry on mobility and the attendant mechanical response of nanocrystalline metals.
||Planned: Supplemental Proceedings volume