报告摘要：

　　Properties of metallic materials depend strongly upon structure and populations of grain boundaries (GBs) and other interfaces. For instance, metals’ strength increases at smaller grain sizes with higher GB densities, especially in the nanometer scale. However, generating interfaces at high densities is technically challenging because they may become unstable under thermal and mechanical activation. In recent decades, we explored different strategies for stabilizing interfaces in metals and discovered several novel metastable nanostructures with extremely-dense interfaces. In this talk, I will introduce (1) extremely-dense lamellate structures with low-energy interfaces (such as nano-twinned structures and sub-nanostructures with negative-excess-energy interfaces), and (2) extremely-fine nanograined structures with 3D periodical minimal surface (TPMS) GB networks, namely ‘‘Schwarz crystal’’. The metals with extremely-dense interfaces exhibit superior stability and extraordinary properties comparing with the ordinary polycrystalline counterparts. Formation, structure characteristics, structure-property relationship, as well as perspectives of these extreme crystals will be discussed in a number of metals and alloys.

报告人简介：

　　卢柯，辽宁材料实验室主任，中国科学院金属研究所研究员。长期从事金属材料研究。主要科研工作包括：在金属中发现三种新型纳米结构：受限晶体(Schwarz crystal)结构，纳米孪晶结构，负能界面亚纳米结构。揭示了纳米孪晶强韧化和梯度纳米结构强韧化机制，发展了系列金属梯度纳米结构制备技术。提出利用稳定界面调控材料性能的“材料素化”策略，推动材料可持续发展。曾获Acta Materialia金质奖章、富兰克林•梅尔奖、德国洪堡研究奖、英国剑桥大学Kelly讲座人等荣誉。当选中国科学院院士（2003），德国国家科学院外籍院士（2005），美国国家工程院外籍院士（2018）。入选国家高层次人才特殊支持计划首批杰出人才。