上海大学材料基因组工程研究院学术报告第十五讲
报告题目：Rethinking Defect Structures and Properties（缺陷结构与材料性能）
报告人：David Joseph Srolovitz，Professor，University of Pennsylvania
报告时间：2015年5月11日 9：00
报告地点：校本部E408（上海大学材料基因组工程研究院学术报告厅）
主办部门：上海大学材料基因组工程研究院
摘要:
We often think of defects such as grain boundaries, dislocation cores, surfaces,... as defects with specific, well-defined structures. There is considerable evidence that in fact the structure of individual defects is not well-defined and is statistically distributed. I will discuss our recent work on grain boundaries that shows the extremely wide range of metastable states that are possible and the structural origin of this multiplicity of states. This plethora of states has profound influence on the statistical mechanics of such structures - this puts bounds rather than values on defect properties. The large (near) degeneracy of grain boundary structure suggests that grain boundaries share many properties in common with glasses. We pursue this idea to predict the grain boundary dependence of several physical properties. For example, we demonstrate that many kinetic phenomena, such as grain boundary point defect sink/source behavior, migration, and sliding can be understood in terms of transitions amongst structural states.
