报告题目(中文):变形及弛豫对金属玻璃原子结构及自扩散行为的影响
报告题目(英文):The impact of deformation or relaxation on the atomic structure, self-diffusion and atomic mobility in bulk metallic glasses
报告内容简介:Exceeding the elastic limit during deformation of metallic glasses causes shear localization and work softening. If the deformation is carried out under at least partial geometrical confinement, plastic flow along mesoscopic defects, so-called “shear bands” is observed. Although compelling concerning the generality of existing descriptions, e.g. as an event following avalanche dynamics, most models for shear band initiation or shear band-mediated flow do not take the local structure, i.e. the medium range order, into account. We have performed a comprehensive study concerning the local medium range order, the local dynamics as well as the specific volume inside and outside shear bands before and after plastic deformation. The strain fields adjacent to shear bands have also been analyzed. For identical deformation states as used for structural or relaxation analyses, the self-diffusivity has been determined after the shear has ceased. Selected results obtained by combining different experimental methods, i.e. fluctuation electron microscopy, electron correlation microscopy, radiotracer diffusion and calorimetry serve to discuss apparent correlations between relaxation – or rejuvenation treatments and resulting modifications of medium-range order and the time scales of heterogeneous glassy dynamics.
报告人姓名:Prof. Dr. Gerhard Wilde
报告人简介(中文):Prof. Dr. Gerhard Wilde于1997年毕业于德国柏林工业大学,获得博士学位。他曾在美国University of Wisconsin-Madison、德国the Institute for Nanotechnology at the Karlsruhe Research Center和University of Saarland工作。2006年,他被任命为明斯特大学教授,并担任Institute for Materials Physics所长。Prof. Wilde是纳米和非晶态材料、非平衡系统相变热力学、动力学以及变形诱导纳米结构材料领域的国际公认专家。迄今为止,在Nature Communications, Materials Today, Advanced Functional Materials, Advanced Energy Materials, Acta Materialia已发表150多篇期刊文章,并应邀在国际会议上发表了70多场主题报告。
报告人简介(英文):Professor Wilde graduated from the Technical University of Berlin, Germany, in 1997 with a Ph.D. degree. He has worked at the University of Wisconsin-Madison in the United States, the Institute for Nanotechnology at the Karlsruhe Research Center in Germany, and the University of Saarland. In 2006, he was appointed as a professor at the University of Münster and served as the director of the Institute for Materials Physics. Professor Wilde is an internationally recognized expert in the fields of nanomaterials and amorphous materials, thermodynamics and kinetics of phase transitions in non-equilibrium systems, and deformation-induced nanostructured materials. His current main research interests also include solid-state diffusion and surface nano-assembly, among others. To date, he has published over 150 journal articles (Nature Communications, Materials Today, Advanced Functional Materials, Advanced Energy Materials, Acta Materialia) and has been invited to give more than 70 keynote or plenary lectures at international conferences.
报告人单位(中文):明斯特大学
报告人单位(英文):University of Münster
报告时间:2024-03-04 09:30
报告地点:材料楼A楼526