报告题目:Solidification and solid-state phase transformation of Al and Mg alloys investigated by HAADF-STEM, EELS and APT
报告时间:3月31日 下午15:00
报告地点:西配楼321
报告人:Priv.-Doz. Dr. Jiehua Li Institute of Casting Research, MontanuniversitätLeoben, 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 annulardark fieldscanning transmission electron microscope (HAADF-STEM) imaging and electron energy losss pectroscopy (EELS)as well as atom probe tomography (APT) can provide information about the structure and compositionat 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 effectof Al-Si based alloys, (2) Modification of eutectic Si in Al-Si based alloys, (3) Refinement of eutectic grains in Al-Si based alloyswith 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 two 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.These five 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.
联系人:刘相法