报告内容摘要

The strength and ductility of the nanostructured metals are strongly influenced by its internal boundaries and defects. Whereas the strengthening mechanisms of the conventional high-angle grain boundaries have been well studies in the naocrystalline metals, in this presentation, we will focus on the recent systematic studies of the strengthening mechanism relative to the coherent twin boundaries It is demonstrated that the increasing the twin density, while keeping the grain size fixed, results in a significant increase in strength but without compromising its ductility. In particular, a maximum strength was found in the nanotwinned Cu at a twin thickness of 15 nm, which followed by a rapid softening and a monotonic enhancement in both the strain-hardening and ductility at smaller twin thicknesses. On the other hand, a switchable plastic properties as well as deformation mechanism in columnar-grained nanotwinned Cu with a highly oriented nanoscale twins was found by simply changing the loading orientations. These findings provide insights into the possible promising routes for optimizing the mechanical properties of nanostructured metals by tailoring internal interfaces.

报告人简介

卢磊博士，女，1970年生人，中科院金属研究所研究员、博士生导师、国家杰出青年科学基金获得者，现任国际纳米材料委员会委员。主要从事纳米结构金属材料的制备、力学性能及变形机理的基础研究。与合作者共同提出纳米孪晶强化金属材料的原理，开创了纳米孪晶强化材料的新途径。发表SCI论文70余篇，被SCI文章引用5000余次，获国际发明专利3项，38次国际学术会议特邀报告。曾获中科院院长奖学金特别奖、全国优秀百篇博士学位论文奖、中国青年女科学家奖等奖项。

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