演講:Topological and Atomic-scale Characterization of Grain Boundary Networks in Poly- and Nano-crystalline Materials and its Applications－6/8(五)10:00-12:002012/06/06
國家高速網路與計算中心特邀 Prof. Mo Li (School of Materials Science and Engineering,Georgia Institute of Technology, Atlanta, Georgia, USA) 演講
一、講題：「Topological and Atomic-scale Characterization of Grain Bound ary Networks in Poly- and Nano-crystalline Materials and its Applications」
二、時間：2012/06/08 (五) AM 10:00-12:00
新竹本部 217會議室�台中分部 會議室(大)�台南分部 網路組會議室
演講者：Prof. Mo Li
新竹 :林秀美 小姐(03) 577-6085 Ext.369 e-mail: firstname.lastname@example.org
台中 :王昀倢 小姐(04) 2462-0202 Ext.803 e-mail: email@example.com
台南 :盧建銘 博士(06) 505-0940 Ext.737 e-mail: firstname.lastname@example.org
Topological and Atomic-scale Characterization of Grain Boundary Networks in Poly- and Nano-crystalline Materials and its Applications
Mo Li a, b
a Department of Mechanical Engineering
b School of Materials Science and Engineering
Georgia Institute of Technology
Atlanta, Georgia, USA
Microstructure in polycrystalline materials, either coarse-grained or nano-crystalline, is characterized by the complex topological structure of grain boundary networks which are composed of an array of geometric entities with different dimensions such as grain volume, grain boundary plane, triple junction line, and vertex point. Collectively, they contribute to the materials’ properties. To be able to achieve the desired properties of a polycrystalline material with optimal microstructure is at the heart of materials engineering: From the ancient Chinese Yue Wang Guo Jian sword to high temperature alloys in jet engines we witness a long history of human endeavor in making desired properties by controlling the microstructures in polycrystalline materials.
While some of these entities can be measured from experiment, a large number of them still remain inaccessible, that includes identification of the full range of topological properties and the structure characterization on atomic scales. In this talk, I present recent developed algorithms and numerical methods to characterize systematically these entities in grain boundary networks in polycrystalline samples, which are either from serial sectioning of real polycrystals or from digital microstructures generated using inverse Monte Carlo methods or other method such as phase field method. The rendered microstructures are represented by the topological and geometric properties such as the grain volume, grain boundary area, triple junction length, and their statistical properties. Most importantly we give the atomic coordinates and label the type of the topological entities to which each atom belongs in the polycrystalline and nanocrystalline materials. Such quantitative characterization, unavailable before, enables detailed and rigorous treatment of microstructures in a wide range of modeling applications including both atomistic simulation and continuum modeling. If time permits, I will also discuss nucleation and growth and their relations to microstructures.
Professor Mo Li received his Ph.D. in applied physics in 1994 from California Institute of Technology. After a brief staying as a postdoctoral fellow at Caltech and the Argonne National Laboratory, he joined Morgan Stanley & Co. in New York. He came back to academia in 1998. From 1998 to 2001 he was an assistant professor at the Johns Hopkins University. Currently he is a professor at the Georgia Institute of Technology and a 千人计划特聘 professor in Department of Mechanical Engineering at Tsinghua University. Professor Li's research focuses on understanding fundamental properties and processes of materials, and predicting material behaviors. The approaches used in his research are a blend of those from statistical physics, solid state physics, materials science, metallurgy, mechanics and large scale, high performance computing. His research focuses on algorithm development, simulation, and theoretical analysis.