Introduction：Irene J. Beyerlein，现任University of California, Santa Barbara机械工程系和材料系教授，Acta Materialia/Scripta Materialia编辑，英国物理学会Fellow。1993年于Clemson University获得机械工程系学士学位，1997年在Cornell University获得材料系博士学位，1997-2000年任美国Los Alamos国家实验室J.R. Oppenheimer Fellow，2000-2016任美国Los Alamos国家实验室理论部门高级科学家（Level 5），2011-2015年历任美国Los Alamos国家实验室前沿能源研究中心联合主任、主任，2016年加入University of California, Santa Barbara机械工程系和材料系任教至今。

    Beyerlein教授在复合材料及多晶金属材料的多尺度模拟计算与分析方面有二十多年的经验，同时在金属材料的结构演化和变形机制方面取得了杰出的成果。目前，她已发表超过260篇高水平的学术论文，其中44篇Acta Materialia，H因子45，国际会议特邀报告30余次，出版学术著作一本，与他人合作完成7本专著。目前任University of Lorraine客座教授，同时获得University of New Hampshire女性科学与工程协会和NSF ADVANCE STEM奖，International Journal of Plasticity青年研究者奖, Acta Materialia杰出审稿人奖。

【Title】Twin formation, Propagation, and Intersections at the Mesoscale

Time:  10:00-12:00 am, May. 25th, 2018 

Location:  新材料大楼材料学院第一会议室

Abstract：

  Hexagonal close packed (HCP) crystalline materials, such as Mg and Ti, can provide a potential solution to the ever-increasing portfolio of structural applications that require advanced materials with unprecedented combinations of mechanical properties. Successful incorporation of HCP materials into engineering designs is, however, hindered by their limited plasticity.  Perhaps one of the most important and puzzling underlying mechanisms governing their plastic behavior is deformation twinning, which form in these materials under straining and most often at the boundaries between the crystals. The nucleation of twins both inside the crystal and at crystalline boundaries has mostly been addressed at the atomistic scale level. In our research, we employ crystal plasticity based micromechanics model to establish and understand the concept of first formation of twin embryos, propagation inside crystals and across their boundaries, and twin expansion and apply it to Mg and Ti and many of their alloys of great technical interest. This knowledge and insight will be used to accelerate materials discovery and design of HCP alloys of low-density, high strength, high toughness alloys, reducing weight and fuel consumption.