报告摘要:

A shear band is a narrow zone of intense plastic deformation, which usually indicates failure of materials. Through about 100-year study, adiabatic shear banding (ASB) theory was established, in which local temperature rises permit thermal softening to predominate over strain hardening in bands. Recently, structural softening mechanisms have been proposed, posing a big challenge to the thermal softening based ASB theory. Such a challenge is particularly important for metallic glasses. In this talk, I will first show how the shear band emerges from metallic glasses where three dissipation processes, i.e., momentum, energy and free volume are naturally coupled. The physical origin of shear banding was revealed, and the onset criterion and characteristic time of shear instability were obtained. A concept of the shear-band toughness, describing the critical energy dissipated in a shear band, was developed to understand the shear band evolution. Then I will present under what conditions, the shear bands disappear in metallic glasses. This in turn validates the mechanism for shear banding emergence. This talk will end with two typical applications of shear banding instability in metallic glasses.

 
报告人简介

蒋敏强，博士，中国科学院力学研究所副研究员、中国科学院大学岗位教授。国家优秀青年科学基金、中国科学院卢嘉锡青年人才奖和英国麦克斯韦青年作者奖获得者。2009年6月毕业于中国科学院力学研究所，获固体力学理学博士学位，同年7月进入中国科学院力学研究所非线性力学国家重点实验室工作至今。2013年6月到2014年12月获德国“洪堡学者”奖学金资助赴明斯特大学，开展非晶物理力学性能方面的合作研究。目前主要从事非晶合金的变形与断裂、玻璃物理、激光-物质相互作用、混凝土海水侵蚀等方面的研究。至今已发表SCI论文50余篇，SCI总引673次。曾获2010年中国科学院优秀博士学位论文和2011年全国百篇优秀博士学位论文提名。现为中国科学院青年创新促进会会员、德国物理学会（DFG）会员。
 
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