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In-situ Mechanical Measurement of Materials in TEM

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Analysis and Test Center of Inorganic Materials
The State Key Lab of
High Performance Ceramics and Superfine Microstructure
In-situ Mechanical Measurement
of Materials in TEM
Dr. Zhiwei Shan
University of Pittsburgh
Hysitron Inc. USA
时间:2007515日 (星期二)9301030
联系人:许钫钫  研究员
In-situ mechanical measurement of materials in TEM

Transmission electron microscope (TEM) is usually taken as a tool to investigate the microstructures of the materials after deformation or to reveal the dynamics evolution of the materials upon stress when equipped with a qualitative deformation holder. Scanning probe microscopes, like atomic force microscope, equipped with a force displacement transducer are known to give quantitative mechanical data regarding material deformation. The fundamental mechanical mechanism of materials deformation is usually inferred from above data. However, the absence of the one-to-one relationship between the microstructure and the mechanical curve make the inferred mechanism at best a reasonable speculation. By  incorporating the advantages of these two kinds of instruments, we have recently developed a novel and unique in situ TEM device, named PicoIndenter, which provides an unprecedented ability to accurately measure the force vs. displacement relationship during the deformation of individual nanostructures while simultaneously live-monitoring the microstructure evolution. This presentation will report the current progress in applying our unique in situ TEM device (displacement resolution of <0.5nm and load resolution of <0.5 mN) for mechanical measurement of sub-micro Al grains, nano particles, nano wires, and sub-micron-sized pillars. The underlying physical mechanisms that account for the observed novel experimental phenomena will be discussed.
Bio of Zhiwei Shan
 Dr. Shan received a B.S. in Materials Science and Engineering from Jilin University, China in 1996, a M.S. degree from Institute of Metal Research (IMR), Chinese Academy of Sciences (CAS) in 1999, and a Ph.D. in Mechanical Engineering from University of Pittsburgh in 2005 under the supervision of Prof. Scott Mao. Dr. Shan then conducted postdoctoral research at National Center for Electron Microscopy, Lawrence Berkeley National Laboratory in the emerging field of quantitative nanomechanics studied in-situ in a transmission electron microscope. Dr. Shan joined Hysitron, Inc. in 2006 as Product Line Manager for Electron Beam & Vacuum Instrumentation.
Related publications:
  1. Z. W. Shan et al, Mechanical Annealing of submicro-sized Ni crystals, Submitted.
  2. Oden L. Warren, Zhiwei Shan et al, In situ TEM Nanoindentation, Invited by Materials Today.
  3. A.M. Minor, S. A. Syed, Z. W. Shan, E.A. Stach, Asif, E. Cyrankowki, T. Wyrobek and O. L. Warren. A new view of the onset of plasticity during the nanoindentation of aluminum. Nature Materials, September 2006, vol. 5, 697-702
  4.  Zhiwei Shan, J.M.K Wiezorek, J.A. Knapp, D.M. Follstaedt, E.A. Stach and S.X. Mao, Dislocation dynamics in nanocrystalline Ni,  Accepted by Physical Review Letters, 2007.
  5. Zhiwei Shan, E.A. Stach, J.M.K Wiezorek, J.A. Knapp, D.M. Follstaedt, S.X. Mao, Grain Boundary Mediated Plasticity in Nanocrystalline Nickel , Science 305 (5684): p654-657 2004.