|About this Abstract
||2016 TMS Annual Meeting & Exhibition
||In Operando Nano- and Micro-mechanical Characterization of Materials with Special Emphasis on In Situ Techniques
||In Situ High Strain Rate Tensile Testing in the Dynamic TEM
||Thomas Voisin, Michael Grapes, Yong Zhang, Nicholas Lorenzo, Jonathan Ligda, Brian Schuster, Melissa Santala, Geoffrey Campbell, Timothy Weihs
|On-Site Speaker (Planned)
Understanding nucleation and motion mechanisms of defects such as dislocations and twins, thought to govern the rapid deformation of metals, is critical to predicting properties such as dynamic strength and spall strength. However, observing their motion in situ is a challenge under high rate loading. Rapid TEM imaging was obtained using the Dynamic TEM (DTEM) at the Lawrence Livermore National Laboratory (LLNL) that has a 30ns time resolution and movie mode capabilities. A new TEM sample holder was designed and constructed using two piezo electric actuators working in bending to load samples at strain rates ranging from 10^2 to 10^4 s^-1. New sample preparation methods combining femtosecond laser machining and ion milling were developed to fabricate TEM tensile specimens, from bulk metallic samples, with narrow gauge lengths to localize deformation and increase strain rates. These design considerations and recent in situ observations of deformation in polycrystalline Cu will be presented.
||Planned: A print-only volume