题目：Mechanical properties Characterization of Materials at Multiple Scale

　　报告人：余倩，浙江大学教授

　　报告时间：3月7日（周一）上午10:30

　　报告地点：李薰楼468

　　报告摘要：　

　　Solid materials are very important market consumes in real industry and are holding the leading roles as structural materials and functional materials. Rgardless of the application, the development of solid materials is associated with solid mechanics and microstructure characterization. Traditional mechanical/electrical/thermal testing experiments and material characterization techniques are frequently separate, so they lack the in-situ information resolution required to directly relate the measured properties with individual microstructure evolution events. The broad field of electron microscopy instrumentation development holds great promise for addressing these problems due to its inherently high spatial resolution and the strong interactions between electrons and solids. It is believed to be the ideal tool to exploit materials properties, especially at small scale.

　　Here, I will present recent results investigating materials properties at multiple scales by coupling the in situ TEM/SEM techniques with other characterization techniques such as HRTEM and EBSD. Lightweight alloys such as Titanium, Magnesium, high entropy alloys and Aluminum are chosen because of their broad prospects in industry (especially for applications in the aerospace and automotive industry). We studied the size-related mechanical properties and the deformation mechanisms (e.g. deformation twinning, dislocation interactions) by combining the mechanical data with the real time micronstrutural evolution. The results show strong size effect on both of them and lead to insight into possible approaches to both strengthen and enhance ductility in these materials at the same time.

　　BIO: Qian Yu，Center of Electron Microscopy and State Key Laboratory of Silicon Materials, Department of Materials Science and Engineering, Zhejiang University, Hangzhou, China; email qyuzju@gmail.com

　　Yu earned her PhD degree in materials science and engineering from University of California at Berkeley in 2012. She was a postdoctoral researcher at National Center for Electron Microscopy at Lawrence Berkeley National Lab and UC Berkeley from 2012 to 2014. She joined the faculty of the Center for Electron Microscopy at Zhejiang University in 2014, where she is also a professor in the Department of Materials Science and Engineering. Yu is interested in materials characterization. Specifically her research interests focus on applying in situ electron microscopy techniques to probe into the correlations between structure and properties of materials.