Advancing Mg Alloys: Nanoscale Strengthening Units and their Deformation Physics

Assoc. Prof. Guozhen Zhu, University of Manitoba, Canada

15:00-16:00, November 13, 2023

Yiucheng Lecture Hall (500), Xu Zuyao Building

Biography

Dr. Guo-zhen Zhu, the Canada Research Chair in Mechanical and Functional Design of Nanostructured Materials, now is an associate  professor at University of Manitoba, Canada. Before she joined the University of Manitoba as an assistant professor, she worked as a research professor from 2014-2017 at Shanghai Jiao Tong University. She attended Tsinghua University for her undergraduate studies in Materials Science and Engineering (2007) department and followed her interest in Materials Science to McMaster University at Canada, where she completed her Master in 2009 and her Ph.D. in 2012. She won many local, national, and international awards such as the Falconer Emerging Researcher Rh Award in the area of Applied Science from the Winnipeg Rh Institute Foundation, the Canadian Foundation for the Development of Microscopy Award and the Gerard T. Simon Award from the Microscopical Society of Canada, in addition to young scientist awards from the International Electron Energy-loss Spectroscopy Meeting and European Microscopy Congress.

Abstract

Magnesium (Mg) and its alloy, as a promising candidate for replacing conventional structural materials like steel, however, its high mechanical anisotropy and poor ductility severely hindered its widely applications. This talk focuses on exploiting novel nanoscale structures, i.e., dislocations and grain boundaries, together with their deformation mechanisms, using transmission electron microscopy (TEM) and in-situ techniques, in order to advance mechanical properties of Mg. Novel dislocation structure consisting of periodically spaced dislocations, with/without Gd segregations, are introduced using simple hot-compression routes. The formation mechanism and potential deformation mechanisms are discussed according to dislocation interactions. Nanograins are synthesized using a wedge mechanical polishing approach. To track the morphology and orientation evolution of nanograins, new in-situ setting is proposed. The uncharted details of simultaneously operation of grain rotation, grain boundary migration, and dislocation activities are revealed during deformation.