Woodruff School of Mechanical Engineering
COE/Structural Mechanics Seminar
Plastic deformation in sub-micron dimensions: Insights from advanced in-situ testing techniques
Dr. Daniel Kiener
Friday, February 12, 2016 at 11:00:00 AM
MRDC Building, Room 4211
Deformation mechanisms in small dimensions can be remarkably different from the common macroscopic behavior. On the one hand, mechanical properties are subject to scale once dimensions are reduced into the sub-micron regime. On the other hand, due to the limited volumes the existence of individual crystal defects within the sample strongly affects the mechanical properties, allowing even completely new deformation mechanisms to occur in sub-micron dimensions. Quantitative micro-mechanical tests inside electron microscopes enable a direct observation of deformation as it proceeds, thereby facilitating a more in-depth understanding of the underlying deformation processes. In this presentation, the capabilities of state-of-the-art in-situ testing techniques to analyze the effect of individual crystal defects on the rate dependent deformation of miniaturized volumes or ultra-fine grained materials will be demonstrated. Moreover, recent developments regarding the local determination of residual stresses and fracture properties in complex structures will be addressed.
Daniel Kiener received his PhD in materials science in 2007 at the Montanuniversität Leoben, Austria. After holding post-doc positions in Munich and Berkeley he returned to his former Alma Mater, where he now holds a position as Assoc. Prof. at the Department of Materials Physics. His research focuses on unveiling the deformation mechanisms and fracture properties of miniaturized objects, thin film structures, and nanocrystalline materials. His group develops and employs sample fabrication and testing techniques that allow for quantitative miniaturized static and dynamic experiments to be performed in-situ in scanning and transmission electron microscopes. Moreover, advanced nanoindentation and thermo-mechanical cycling techniques are applied to study temperature and rate dependent properties and structural stability of high strength materials.
Refreshments will be served.