时间：2023年11月9日（周四）15:20-17:00

Time: 15:20-17:00, Thursday, November 09, 2023

地点：西湖大学云谷校区E10-212

Venue: E10-212, Yungu Campus

主持人:  西湖大学工学院PI 杨尧博士

Host: Dr. Yao Yang, PI of School of Engineering, Westlake University

语言：中文

Language:  Chinese

主讲嘉宾/Speaker：

Prof. Qian Yu 余倩

School of Materials Science and Engineering

Center of Electron Microscopy

Zhejiang University

主讲人简介/Biography:

Qian Yu is a Professor at School of Materials Science and Engineering and Center of Electron Microscopy, Zhejiang University. She obtained her BS degree and MS degree from Xi’an Jiaotong University (2004, 2009), PhD degree from University of California, Berkeley (2012). Her research interests are using advanced characterizations to explore the structure-property relationship in Metals.

More information about the speaker can be found in the link: https://person.zju.edu.cn/yuqian.

讲座摘要/Abstract:

Inelastic interactions between dislocation cores and other crystal defects are critical factors in modifying materials’ strength and plastic deformation. However, due to the complexity of dislocation core structures and severe distortions there, scientific understanding of these interactions remains incomplete. This is especially true when heterogeneous structures (clusters, short-range ordering, precipitates, etc.,) are present in materials, making the contribution of non-elastic interactions to materials’ mechanical properties even more significant. Using multi-scale and in-situ transmission electron microscopy characterizations, combined with three-dimensional tomography and simulations, we reveal the influence of three typical types of heterogenous structure in enhancing the inelastic strain energy of dislocations. In complex alloy system, we found the existence of nanoscale compositional fluctuations, which plays important role in tuning dislocation behaviors. A new strengthening model was built accordingly. In micro-alloying system, certain alloying elements prefer to segregate at dislocation cores, intensifying the inelastic interactions between solutes and dislocations and resulting in abnormal dislocation strengthening. In multi-phase system, we reveal a non-classical nucleation mechanism in solid-state phase transformations, based on unique elemental diffusion behavior. This can create novel nano-sized heterogenous phase structure, which shows strong inelastic interaction with dislocations, significantly enhancing materials’ strength and/or plasticity.

联系人/Contact：

朱松梅

zhusongmei@westlake.edu.cn