报告题目：Deformation Twinning in Hexagonal Metals

报告人：Prof. Jian Wang

主持人（邀请人）：王慧远 教授

报告时间：2019年6月8日上午9:30

报告地点：南岭校区材料馆209学术报告厅

主办单位：材料科学与工程学院

摘要：Twinning and de-twinning, which are the dominant deformation mechanisms in hexagonal-close-packed (HCP) metals, exhibit more complex nucleation and propagation mechanisms than those associated with dislocation slip and those in cubic structures (FCC and BCC). Specifically, twinning and de-twinning are directional, involve atomistic shuffling, and they induce a strong crystallographic reorientation. Twin nucleation, a necessary first stage of twinning, seems to invariably take place at grain boundaries in hcp materials, and to involve complex dislocation reactions. After twin nucleation, twin propagation and growth seem more complicated than that in cubic crystals because of the formation of serrated coherent twin boundaries. In this talk, I will focus on the fundamental understanding of nucleation, propagation, and interactions of deformation twins and their effects on mechanical behavior according to atomistic simulations and in situ microscopic observations. These findings provide theoretical base for researchers to revisit experimental data, rebuild the frame of twinning mechanisms including nucleation and propagation of twins, and advance the development of materials modeling tools at meso- and macro- scales as well asalloy design.

报告人简介：Dr. Jian Wang is a full professor of Materials and Mechanical Engineering at the University of Nebraska-Lincoln. He received his Ph.D from Rensselaer Polytechnic Institute, Troy, NY, USA, in 2006, and worked at Los Alamos National Laboratory (LANL) as technical staff member for 9 years. His research focuses onquantitatively exploring the structure-properties relations of structural and nanostructured materialsusing multi-scale theory, modeling and experimental methods and techniques.He was awarded the LANL Distinguished Postdoctoral Performance Award (2009), the LDRD/Early Career Award (2011), two LDRD-ER Awards (2013), TMS MPMD Young Leader Award (2013), International Plasticity Young Research Award (2015), Journal Outstanding Reviewer Awards for Scripta Materialia (2016),Modelling and Simulation in Materials Science and Engineering(2016), and Acta Materialia (2017), and Materials Today 2018 Rising Star Award in the category of Materials Genome Innovation (2018). He served as Editorial Board of International Journal of Plasticity (2015~), Scientific Reports (2016~), and several others. He has published more than ~250 peer-reviewed papers (> 9000 citations and H-index = 58, 25 papers selected as Hottest Articles in Materials Science, and 7 papers featured as Journal cover), and delivered 100+ invited/keynote presentations.