1. 报告题目I:Solidification of metal melts
报告题目II:Solid-state phase transformation of metal alloys
报告人:Jiehua Li 教授
Institute of Casting Research, Leoben University, A-8700, Leoben, Austria
In the fields of solidification and solid-state phase transformation of metal and alloys, a number of key problems, for example, heterogeneous nucleation during solidification and solute clusters in solid-state phase transformation, still need to be revealed at the atomic scale. High angle annular dark field scanning transmission electron microscope (HAADF-STEM) imaging and electron energy loss spectroscopy (EELS) as well as atom probe tomography (APT) can provide information about the structure and composition at the atomic scale, which have been widely used in the fields of solidification and solid-state phase transformation of metal and alloys. In terms of solidification, this talk will present the following three aspects of research works: (1) Grain refinement of Al alloys (via TiB2, AlB2 and Al2O3) and Si poisoning effect of Al-Si based alloys, (2) Modification of eutectic Si in Al-Si based alloys, (3) Refinement of eutectic grains in Al-Si based alloys with a focus on the interaction between the modifying agents and heterogeneous nucleus particles (AlP). In terms of solid-state phase transformation, this report will present the following three aspects of research works: (4) Solute clustering and precipitation of Al alloy during the early stage of ageing, with a focus on the interfacial structure and defects of Al-Au and Al-Cu-Au based alloys, respectively. (5) Solute clustering and precipitation of Mg alloy during the early stage of ageing, with a focus on the Mg-Zn-Gd and Mg-Nd-Gd(Y)-Zn based alloys, respectively. (6) Microstructure evolution of Ni-based K430 superalloy during thermal exposure. These six examples strongly indicate that HAADF-STEM, EELS and APT play a very important role to elucidate key issues in the fields of solidification and solid-state phase transformation of metal and alloys.
主持人:材料学院新结构材料实验室王晓东副教授
报告地点:玉泉校区,教六-231房间
报告时间:2017年3月30日下午14:00
联系人:王晓东电话: 87952107
联系人:王晓东电话: 87952107
欢迎广大师生参加!