简介: |
abstract
Nanostructured materials usually have high strength but low ductility. Past attempts to increase the ductility usually led to a decrease in strength. To improve their ductility, we need to first understand their deformation physics. In this talk, I’ll first present the deformation physics in nanostructured materials, including partial dislocation emission from grain boundary, twin formation mechanism, grain size effect on twinning, general planar fault energy effect on twinning, and partial multiplication mechanism. Then I’ll present how to use deformation twins and several other strategies to improve the ductility without sacrificing the strength. We have been able to simultaneously increase the ductility and strength using these strategies. Lastly, I’ll present the effect of the specimen size on the mechanical behaviours of nanostructured materials, which may present some challenges in interpreting the observed strength, ductility, strain hardening, etc.
Biography:
Professor Yuntian Zhu, North Carolina State University
Ph.D. Mater. Sci. Eng. The University of Texas at Austin, 1994
Dr. Zhu was the team leader of the Nanomaterials Team in MPA-STC, Los Alamos National Laboratory before he joined the NCSU faculty in 2007. Zhu’s research in recent years has focused on two major nano-related areas: metals and alloys with nano/ultrafine-grain structures, and synthesis and applications of carbon nanotubes. His research team has won two Nano50 Awards. He recently received the 2010 TMS MPMD Distinguished Scientist/Engineer Award and the NCSU Alumni Distinguished Research Award. More information about Dr. Zhu’s research group can be found at http://www.mse.ncsu.edu/zhu/
联系人：
岳振星 老师 62787647
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